I preached it for thirty-seven years. Ran myself in circles just as you are doing to yourself.
1 Corinthians 9:24-27
24. Do you not know that in a race all the runners run, but only one gets the prize? Run in such a way as to get the prize.
25. Everyone who competes in the games goes into strict training. They do it to get a crown that will not last; but we do it to get a crown that will last forever.
26. Therefore I do not run like a man running aimlessly; I do not fight like a man beating the air.
27. No, I beat my body and make it my slave so that after I have preached to others, I myself will not be disqualified for the prize.
Paul saw the problem that you describe, and took pains to avoid it.
To me, I see faulty logic in your conlusion. Starting with THIS premise -
If you are in that group that says we can avoid sin entirely, but we "choose" to sin anyway --
you build on it to a conclusion: But it's your fault.
When I was born, I could not swim, but it was no more my 'fault' than my mother who bore me: it's just the way it is.
However, I learned to swim, thus 'saving myself' from the sentence of the water.
Because I have a 'sin nature' is also not my 'fault'; it's just the way it is. But I CAN do something about it.
You are not completely doomed - there's a verse somewhere that says - "come to your senses".
It's my opinion that....
Ol' Hank wouldn't done it thataway!