I want to crash out and text my ex

My ex (34M) did me (23F) so dirty. he treated me like absolute shit for over 3 years. I was so young, came from an abusive family, had nobody and I just accepted it back then. He used me, lied, hid things, cheated, made me feel horrible, shamed me for everything, didn’t want me to grow, to have friends etc. After we broke up for real almost a year ago, it really hit me how bad it was.

He never cared about my feelings. No matter how much I cried, begged, confronted him he would go cold, ignore me, threaten to leave me or act like nothing happened. It was exactly like my childhood all over again and I just shut down and endured it at some point. Even when I tried to speak up, he didn’t change. Months later, he still poped up acting like everything’s fine, even asking me for favors ?! But he never took any accountability. I finally realized he’ll never change and that I’m not safe with him & stayed away.

Last week we ran into each other. He acted super nice like nothing ever happened & I was nice back. I don’t even know why I responded that way, maybe out of shock but I definitely didn’t ask anything about his life. Now I’ve also seen him on dating apps and literally with another girl and it’s sent me into a rage. It feels so unfair he ruined me, never owned up to anything and just gets to live his happy little life like nothing happened, while I’m left with all the pain.

I’ve never fully confronted him with everything he did because he’d just ignore me or shut me down. I never even screamed at him, we barely argued bc I was scared of him. But now I’m seriously thinking of sending him a long message, laying out everything I’ve held inside for years and then blocking him for good. I already have him blocked, but I can’t stand the thought of him believing I’m fine and that we’re somehow good I want to tell him for once what kind of shitty horrible person he is