It's amazing and wonderful to me that someone with these tendencies is actually self-aware AND wants to stop. Maybe that's more common than I thought. There are good therapists and bad therapists, but if you could figure out why you're doing it and face the inner self behind it (probably a wounded/abandoned/hurt kid full of self loathing because someone doesn't love him/her the way they should), and face what happened to you... then you may be able to stop.

Another thought is that not everyone with these tendencies was mistreated. It's just more common. In either case understanding why you do it, how it hurts others (perhaps in merely functional terms if you lack empathy) and how it ultimately hurts yourself may help you.

Another thought... you may have a vision of the kind of world you would like to see - the kind of world you would wish for. Unless it's a world where people are hurt, suffer loss of potential, and live those consequences then it's perhaps a more healthy view. If so, maybe you can use your view, your values, as motivation to stop. Ask yourself whether you are creating the world you want to be in. Think of your values as your code for behavior choices - not just pie in the sky.

Since you're used to pain based gratification, it will be hard to stop. It will require repeated practice on your part, like learning a new instrument. But you can do it. And as a help, maybe you can take some small gratification in the fact that you could have hurt someone, but that you CHOSE not to.

Wish you motivation and caring enough to stay in touch with your better self!