DBM,
My heart really hurt, reading your post - I guess I recognize a lot of myself in there. But I have never felt abandoned by God. My conscience has surely been seared, too. But the funny thing is, I KNOW when I'm supposed to be feeling or thinking something I'm not. So I act on the knowledge without the conviction. The funny thing is, as you do that, "acting" as if you did have it, it slowly returns! God can replace what the locusts have stolen, I have seen it in my life. It usually isn't all at once, and sometimes you have to reflect over long stretches of time to see it. Some things take years to heal.
Feeling distant from God is hard. David felt it too - perhaps you should bury yourself in his Psalms. For me, I feel that the problem has ever been my inability to come to Him properly, sin or no, although perhaps he is proving you.
Are you trying to do this alone? I think it would be beneficial to be a member of a Christian group. I sometimes find myself face to face with God while loving / serving someone else. Fast? Pray for long stretches? Expose yourself to beauty of landscape or music or art? Just some suggestions, perhaps you've been through them all.
With respect, I don't agree with your repentance theory. Repentance is contriteness with intent to correct. If you think you have it, you do. God knows we can stumble. Can anyone claim they've been sinless in actions since they were born again? *waits for reply...
* Umm... silence. (Except for Dave_Ulchers claiming that someone else is doing it that is...) You WILL sin again while you live. Everything else is a matter of degree. When Christ died for you, all your future sins were forgiven, both the ones behind you now, and the ones to come, if you are in Him. Covered. Righteous. Blood bought and sealed. Agree with your eternal security ideas and the idea here that the subject matter of Hebrews is over the issue of sacrifice. Remember though, sometimes salvation is "as if by fire" or whatever the phrase is to say you just barely made it, with no good works to show. Let's not settle for that by sinning!
I'm sorry to have rambled a bit. I will pray for you, friend, that the freshness and power of new life will again come upon you, and that you will awaken to the Holy Spirit working in you.
In Christ,