Did I do the right thing by secretly leaving him? (A long read)?

You were right. He is a game player and is mentally abusive. He cannot deal with relationships and doesn't deserve to be in one. You deserve better, and if there was one thing I would say you didn't do quite right was only not drop his *** sooner. I mean that. You'll be fine, you didn't deserve any of that AND he needs to learn that the way he acts is not right. And he needs to learn that on his own, not with you. Take care.