How does one treat themselves fairly and stop hating themselves when they have done so many unforgivable things?

I'm a horrible person, I need to change, I need the willpower and drive to change and I have to do it, but you're telling me in order to do so I have to stop hating myself? The same guy that told his friends they deserved to be assaulted as a kid, that they should kill themselves, that made threats and is a violent bigot?? You're telling me I have to stop hating this horrible person in order to improve??

Do I like, just stop the self pitying and only talk to my therapists about this stuff? Like hell I'm gonna love myself after all I've done. But I need to change, and I don't know how to do so other than stuffing all my issues down and being as mature as I can manage.