IWTL how to forgive myself

I'm a complete failure at everything, and by all rights shouldn't be alive. But I'm finally in a relationship with someone who's worth it, and I don't want to die anymore. But I can't lose this one bit of happiness and dignity, and for that I need to function like a real human being rather than the garbage I was my entire life. I need to forgive myself for never learning anything useful or profitable and for wasting my entire youth. I need to learn how to want to live.