Going through life I've always felt like I'm an awful person.
Why would you think you're an awful person?
I don't have much self-esteem. I dislike myself.
It's okay to not always feel good about yourself. Maybe you can talk to a therapist if you're having difficulty with self-esteem, you shouldn't feel awful about yourself.
I feel better now, since I told myself these things
I'm glad you feel better now, but I think therapy would be highly beneficial for you. It's always good to talk to someone about your problems and they could help with your mental health.