studier said:
My apology for being slow. Daily life is consuming quite a bit of my time, so I'll be in and out of here.
I'm going to supplement your explanation of Total Depravity with this explanation which seem to have sufficient similarities to what you've said. I don't know if you'll agree with what it says, but it affords me the resource to read further and not have to bother you with some questions. If you'd like to provide a different resource, I'll look at it. I'm also looking at some of what @maxamir has provided graphically.
From: https://www.apuritansmind.com/tulip/the-five-points-of-calvinism-by-w-j-seaton/
[cut drastically to save space]
No apologies needed, my friend. As they often say in Swampland where I live (FL), "I'm up to my armpits in 'gators, also". 
But let's see if we can try to cut to the chase of the Total Depravity doctrine. But first, I'm glad that you did say that there "seems" to be a contradiction between the distinction Reformed folks make quantitative and qualitative corruption of men's hearts. I'm well aware of this objection by NR (non-reformed) folks, which is why earlier I cited Gal 5:9 and Jas 3:11-12, as these are very important spiritual principles. In fact, this principle expressed in terms of "leaven" (evil) initially appears in scripture at the first Passover instituted in Egypt whereby the ancient Israelites were forbidden to have any leaven in their households during Passover season. They were required to get rid of every trace of leaven until after Passover. I could be wrong, and I stand to be corrected here, but this spiritual principle seems to be teaching that God requires nothing less than absolute/perfect holiness and righteousness of his moral creatures, and and anything less than this is abhorrent to a thrice Holy God. One act of sin is enough to condemn any rational, moral creature of God to eternal damnation.
The second thing I wish to caution against is that both sin (lawlessness) and godliness are mysteries (cp. 2Thes 2:7 and 1Tim 3:16, respectively). So, I don't think we're going to understand totally how sin and godliness work in the human heart -- at least not in this age.
Thirdly, while all men come into this world in Adam, which to me further means, we all come into this world as seeds of the Serpent;. nevertheless, at the same time, we also come into this world as God's image-bearers. Being that we are created in his God's image. While sin is a fatal disease of the heart and soul, if left untreated by the Great Physician, in that it has greatly marred that divine image in us -- it has disfigured it -- distorted it, which means we can't fully understand on our own what that image really means -- nonetheless it's this image that basically instills in man a God-consciousness, which I actually prefer to call a Religious-Consciousness; for it certainly seems that most men sense they have a duty to perform before some power greater than ourselves. And this truth in borne out in Natural Revelation with the plethora of world religions from which to choose.
Having said all that, let me pop a big question at you that has to do with this passage:
Luke 18:18-27
18 A certain ruler asked him, "Good teacher, what must I do to inherit eternal life?"
19 "Why do you call me good?" Jesus answered. "No one is good — except God alone. 20 You know the commandments: 'Do not commit adultery, do not murder, do not steal, do not give false testimony, honor your father and mother.'"
21 "All these I have kept since I was a boy," he said.
22 When Jesus heard this, he said to him, "You still lack one thing. Sell everything you have and give to the poor, and you will have treasure in heaven. Then come, follow me."
23 When he heard this, he became very sad, because he was a man of great wealth. 24 Jesus looked at him and said, "How hard it is for the rich to enter the kingdom of God! 25 Indeed, it is easier for a camel to go through the eye of a needle than for a rich man to enter the kingdom of God."
26 Those who heard this asked, "Who then can be saved?"
27 Jesus replied, "What is impossible with men is possible with God."
NIV
What do you make of this passage? Should we take Jesus literally here when he said "No one is good, except God alone"? Or was he using hyperbole for some reason? But if we do take him literally, then how can we not logically infer that man must be evil, since he's not good? And Jesus was certainly not shy about calling a spade a spade, was he...ever? How many times did he call the Jews "evil"? "if you being evil know how to give good gifts to your children...(Mat 7:11). A text like this certainly seems to bear out my understanding of Total Depravity, which again doesn't mean that all men are as evil as they could be -- and this due to multiple factors which I won't discuss here to save space and time.
In fact, returning to the Luke passage above, it's obvious this rich young Jewish ruler was likely a very religious guy. First, he approached Jesus respectfully, unlike most leaders in the Jewish religious establishment. And this rich man appeared to be sincere with respect to how he kept the Law. He seemed to respect the Law, as well. But look what happened once Jesus ingeniously revealed this man's "hidden sin" -- a sin that certainly seemed to be hidden from this ruler's mind and heart. He loved something more than God, and apparently he was not aware of his sin! It appears he was far more conscious of his "law-keeping abilities". I don't know how this strikes you -- but for me, this speaks sharply to this religious man's self-deceived heart.
When this man's sin was revealed, he became "very sad". And Jesus even conceded to him that those who love money have a really, really tough time entering the kingdom. Why was he sad? Could it be that he "desired" to please God on his terms and not on God's, and Jesus exposed his hypocrisy?
The next question that comes to mind: Did Jesus think this rich man was evil also, or was he a pretty good guy trying to do his best?
Jesus' reply to this rich man astounded his disciples and prompted them to ask the very urgent question, "Who then CAN be saved"?
So, the next question begging to be asked, was Jesus' reply in v.27 more gross exaggeration or did the Lord literally mean that "what is impossible with men is possible with God"? But notice, too, that Jesus didn't answer the question of "who" can be saved. Rather, he told his disciples HOW anyone CAN be saved! We shouldn't miss the Lord's answer.
I'll close this post with an analogy taken from Natural Revelation. How I double-check my theology derived from Special Revelation is that it must comport well with Natural Revelation. If it doesn't, then my biblical theology is wrong. It's back to the drawing board . So...if we liken Sin to a deadly poison, how much sin would be fatal to us? And what are the odds that if someone becomes deadly poisoned in one way or another that that person would actually know what toxin has infected them, and have the know-how and the resources to treat themselves quickly enough to survive? Let's liken Sin to this toxin stated below:
Scientists differ about the relative toxicities of substances, but they seem to agree that botulinum toxin, produced by anaerobic bacteria, is the most toxic substance known. Its LD50 is tiny – at most 1 nanogram per kilogram can kill a human. Extrapolating from its effect on mice, an intravenous dose of just 10-7g would be fatal to a 70kg person.
The article ends with this fascinating observation:
As Paracelsus is reported to have said 500 years ago: “All things are poison, and nothing is without poison: the dose alone makes a thing not poison.” And he had a point. Ultimately, we are surrounded by potentially dangerous substances – it’s the dose that makes it deadly.
https://theconversation.com/handle-with-care-the-worlds-five-deadliest-poisons-56089
How much underground sea water seepage would it take render a well usueless? How much leaven would it take to ruin a heart? Or how much bitter water would it take to ruin sweet spring water? While poisons ususally attack limited areas of the human body, e.g. liver, kindneys, heart, nervous system, etc., it seems that Sin is even more pernicious as it attacks ALL the human faculties, not just one or two. The entire heart of man is corrupt with evil, not just parts of it! There is no part of man's Soul that is not poisoned by Sin.
So...if you ask:"Well, then how can someone 'do good' to his fellow man, for example, and still be classified as spiritually dead", I would respectfully suggest that you're asking the wrong question. The question should be: Why is it that man cannot not sin? Why is it that man born of a woman cannot be pure before God? Could it be that the biblical answer to these types of questions is that: How can the Dead do anything that fully and continually pleases, honors and glorifies God? Only Jesus did these things always. Always! Did He come into this world in Adam? Did He come into this world spirituallyn stillborn? You're not making sense out of the doctrine of Total Depravity because you're asking the wrong questions and you're not making the ONE and only right comparison that should be made -- the one between the sons of Adam and the Last Adam. When the bar of Holy Perfection is raised to the Second Man, then we can begin to make sense out of the biblical doctrine of Total Depravity that affects all the Sons of the First Man.
