I am not sure if I am going to have a chance to be happy in life. It is really my own fault though.
What makes you think that it is your fault personally that you may not be happy?
I have always tried to be the opposite of my tortured homelife
You are you, and no one else is in a position to define you. Have you considered moving out? Or if that's not possible, seeking counseling?
If I want to help myself I need to stay here, I'm still young at 21 years old
Just know that you will be happiest in your life being yourself. If you are upset at home and feel like you can not get out of the situation, do not hesitate to reach out for help.