How do you genuinely become a better person?

1. Respect yourself: stop giving yourself permission to treat yourself worse and place less value on yourself than other people. Don't put up with mistreatment from others. Ever. When you put a value on yourself people will rise to it. Don't do stupid, self-destructive things that reaffirm your instinct to devalue yourself.

Actually, that's a good start. If you do that you'll have momentum. If you're already doing that I can give you good next steps...