I Miss My Ex Boyfriend But When I'm With Him I Don't Want Him Anymore, What's Wrong With Me?

I think if you look closer, you may find it actually is not him that you miss. At least that's what it sounds like. More likely you miss what you got from the relationship; relief from boredom, emotional support, affection, etc.

I am going through the same problem at the moment, my ex has a new girlfriend and I am suffering. He was still interested in me until about a month ago and now he has someone new, but I did not want him back at all, quite the opposite, even though we get on really well. I know he is not the right one for me!
I think it is ok to feel that way, that you miss him, but I would not act upon it, since really you are missing the affection, the comfort of the relationship, the fact that you are no 1 for someone and not the actual person itself.
Breaking up is not nice and it is like a small death somehow, and that is why you are feeling the way you are. As mentioned before, you might be better off not seeing him and do your own thing for a while and time will just sort this problem out for you, or you will find someone that you love for who they are and not just as a partner that is there for you! Just remember to be fair to your ex and not mess him around!

Hun I went though the same thing. I feel its the feeling of being comfortable that you miss. The good times you miss.. But when you reinact with him, you are over him. So you don't care. But when your not with him you think of how things were. And how comfortable you were. At least. Thats what I missed. I just stopped all contact. As hard as it was. Now I'm in a new relationship that I love. And hes just a distant memory of what use to be :). Hope this helps hun. Good luck