If a guy ever drastically lowered your self confidence/self worth, I need advice

My ex really destroyed all that for me. He was extremely verbally abusive, he’d call me names and put me down about everything. I stayed with him for so long because he had me convinced I couldn’t do better and no one would love me.

And even though I did leave him, I just can’t lift myself up. When a guy acts like he likes me, I don’t trust it. I still feel everything that my ex made me feel about myself. How can I change that? How can I work on it?

-I’m not dating, and I can’t afford therapy