I haven't told this to anyone, but I hate the "past-me."
You mean the person you were in the past?
Yes. Past-me made a lot of mistakes that are causing present me suffering.
Past you is still you.  It's not healthy to hate yourself.  Everyone makes mistakes!
Fuck Past-me!
If you're feeling depressed about how your past has affected your life, you should explore your feelings with a counselor. Counseling can help you resolve the conflict between your past and present selves.