I dont think we can comment on him having issues because of his reason for dumping the OP. We know nothing, maybe the ex still wants to be with the OP, or the OP has made it obvious in some way she still has feelings for her ex.
Obviously this is an issue of power. They have split up before and got back together, and thus he knows that the OP will ALWAYS go back to him, so he can exert his "power" when he feels like it. Dont be suprised if the next time you speak to him he says something "Ok, we can go back out, but only if you NEVER speak to your ex again."
It's a way to show you what he can do, and to then get you to act exactly how he wants you to act.
I strongly believe that every relationship needs a leader and a follower, and the follower certainly has to take some *****, but they are willing to do so. The leader will always be a bit of an a**hole, but then maybe they are then running the risk that the follower will one day find a better leader.
To the OP. Dont be upset. Have a few hours to yourself, listen to some music and do some thinking. If you want him, he's yours. He is the insecure one, so he needs you more than you need him. If you think he's out of order and you could do better, then you're lucky - you weren't in love.