Does the Bible talk a lot about forgiving oneself? Not really. There would have been some pretty good places where, if self-forgiveness was paramount to our relationship with God and others, it would be dealt with in the Scriptures: David, after he essentially murdered Uriah and committed adultery with Bathsheba, Peter, after he denied the Lord three times, Paul, for persecuting the church.
The closest the Scriptures deals with the idea of "self-forgiveness" is Romans 7 in which Paul deals with the fact that believers deal with the nature towards sin and the fact that, as Christians we now abhor the sin. Do read Romans 7:14-Romans 8:2. I believe that this should be required reading for every Christian. He sums it up with this: "Wretched man that I am! Who will set me free from the body of this death? Thanks be to God through Jesus Christ our Lord! So then, on the one hand I myself with my mind am serving the law of God, but on the other, with my flesh the law of sin. There is therefore now no condemnation for those who are in Christ Jesus. For the law of the Spirit of the life in Christ Jesus has set you free from the law of sin and of death." (24-8:2)
So, essentially when the bible deals with our inner loathing of our sinfulness, we basically see that, yes, there is that loathing, but that's actually a good thing, it's a good thing because it means that we are in agreement with God about our sin and that agreement means that the law of sin has been broken within us and we are now free in Christ. This is different from those that try to say, "it's OK to continue in sin, because Christ forgives".
What about continued self loathing, then? Is this really a problem? Consider that God's word tells us, "for no one ever hated his own flesh, but nourishes and cherishes it, just as Christ also does the church".(Eph 5:29) If it is true that no one truly hates himself, then why self-loathing? Well, think about it, self-loathing is really just another form of self-absorption. Yes, we are concentrating on how much we fail God, but nonetheless, the concentration is still on our self. And, therein lies the problem. We need to get out of the practice of concentrating on self so much. As Paul, who sinned very much against the church did, we need to "set (our) mind on the things above, not on the things that are on earth." (Col 3:2)
So, here is Handy's simple "3 step" program toward "self-forgiveness":
1: Agree with God that your sin is bad.
2: Get over yourself already! ;)
3: Set your mind instead on the "things above".