I'm a terrible person most of the time.
What makes you think you are a terrible person?
I steal from others very often.
Realizing you are not a good person is a good first step. You need to stop stealing from others, as you know that is not good to do.
I'll keep doing my thing, because that is all I know how to do.
You can change your behavior if you try to. There is no need to be stealing from others like this, since you know it is bad. Have a family member or friend hold you accountable for your actions.