antisocial personality disorder

[interested]

I recently broke up with my boyfriend of 5 months. It was his erratic personality and heavy emotional swings that eventually lead me to this decision.
But after having a few days to ponder who he actually was, and why he phased me so, I came to the conclusion that he had a serious psychological condition.

I am 4 years younger than he is, and he is the most soft and gentle person I know. He is also violently clingy and protective of me. During our relationship he completely used me to verify his own emotions and to make him feel better about himself. He would ignore me and tell me horrible and provoking things just to watch me run back to him. Then when I said one word out of line to him, he would immediately shut down and enter a catatonic like state.
After considering a trend in his last 4 girlfriends, I came across an interesting discovery which led me to my final conclusion about him.

He preys on the emotionally unstable.

These girlfriends have all in some way been emotionally or psychologically unstable. Each having either anorexia, depression or social anxiety.
After dating them for a few months, when the relationship began to get a little weaker than it's earlier days, he would subtly drift away, and 'replace' them with a new girl (not even necessarily a girlfriend or partner, just somebody who fascinated him).
When we first began talking, he didn't pay much attention to me; but after 2 days I mentioned my former anorexia and OCD and he didn't hesitate when he asked me out the next day.
He would constantly hide his own emotions from me, yet encourage me to be open about mine, in order for him to 'help' me.
He was always asking questions "How do you feel about that?" and such.

In a way he was almost siphoning my emotions and energy and using them for himself. Sick, huh?

I think that it may be appropriate here to mention that his father died when he was 5 years old. And that he himself suffered from anorexia for 3 years.

So as with his other relationships, after our few months of relative peace, we started to see each other less, and he started to talk more about 3 new girls he'd started talking to. An anorexic, a schizophrenic, and an anxiety case.

I asked him simply "Have I been replaced?" and he replied "I guess so."
I'm just so annoyed that I hadn't put two and two together earlier on.

So, at the end of this rant, I ask you budding psychologists and general readers- what kind of a condition, disorder or syndrome does my ex-boyfriend suffer from, with the combination of the aforementioned symptoms and behavioural patterns?
I would be very interested to know.

Thank you, and regards!

[S. Earl Martin]

It is good you are aware of your situation and how it is effecting you. I am not a psycholigist, but your ex boyfriend may be Bi Polar. I am Bi polar and I have struggled for as long as I can remember. Sounds like a possibility. Many Bi polar individuals tend to seek out people weaker than themselves and use intimidation to get their way. Of course diagnosing someone without actually seeing them is very difficult, but from what you have said it seems plausable.

It is best to set goals that help you measure progress in your life. If you are in a situation that is counterproductive? A determination must be made as to what is the best course of action. What is it you want from a boyfriend or from life in general. Work toward that end. 

Good luck and stay positive. Earl