Typically when a relationship ends, people stop talking to each other. At least, they do if they want a healthy break-up. I've dated a few crazy and abusive women at the time. As far as I can tell, the only thing I did wrong was choose to date them in the first place. Most likely at worst he's into co-dependent relationships and/or drama. It sounds like he has some baggage with crazy ex's that he has to deal with.
But really you're not giving us to suggest that either you or he is crazy, or that there was something wrong with the relationship. Perhaps you just weren't a good fit together.
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."