When I was a younger I used to think that because I felt guilty about my sins, that meant I was repentant. It took me a while to puzzle out the difference. I was confusing to myself when I observed that I kept on sinning; hadn't I repented? I thought I had, but I was wrong.
Guilt is an afflictive emotion that arises when we become conscious of having done something against our conscience, our best selves, or who we have decided we want to be. Like other afflictive emotions such as anger and dejection, guilt isn't really moral in itself. The moral decision arises when we decide what to do with our guilt, and there are two choices.
Guilt presents a temptation and an invitation.
The temptation is to transform guilt into shame. We go from realizing that we have done something wrong to believing that we ourselves are bad. We go from hating the evil we have done to hating ourselves. In this movement we are tricked into an inverse form of pride that is just as self-involved as any positive vanity. In our concentration on ourselves, we start to miss out on grace. We lose interior sight of the God who alone can free us from the rotten luxury of our particular self-involvment, and we end up reinforcing the selfish roots of sin that got us into the whole mess in the first place.
The invitation is to turn guilt into repentance. Repentance wants to get rid of guilt not because it will make us feel better, but because we want to be better. We want to be rid of sin because, having discovered that we are beloved of God, we trust God enough to confess that we are a creature lovable enough to deserve better care, and more happiness. Even if we don't yet love ourselves well, we can desire to care for ourselves better as Another's beloved.
In other words, the path to real repentance is not so much in hating sin, but in loving the God who has loved us first.