Perhaps it’s just that I still more or less believe in the Path to Perfection, that we can and will reach perfection wil multiple, limited lives (if we try), and I do feel that if that is true, each life holds one major sin/temptation in each life.

Pure grace is entirely too difficult for me to wrap my brain around, lol.

your sin . . . has to be conquered absolutely and without that true repentence cannot be reached.

I think you have that backwards. I think it’s the true repentence that helps you conquer the sin. Not, perhaps, that one ever conquer’s one’s sins once and for all. We may grow out of one here or there, or now and then, but given the evidence of very spiritual people, we don’t ever conquer them abaolutely.

Further, for something that is as deep as you are saying, isn’t part of the idea that we can’t do it by ourselves, that part of God’s grace is to help us do what we can’t do by ourselves?

Anyway, whatever it is you’re battling in yourself, may God be there battling it with you, and may you feel God’s presence with you. And if you need other people to help you–may God lead you to them.