I think it is the fact that my boyfreind and I split too - well, actually we didn't split as such - he is in prison but has not contacted me since before he went in, over 2 months ago. I only know what I know through a friend of a friend of his, so I have a lot of unanawered questions about that too and I miss him so much.
Maybe you need reassess the type of people you get involved with otherwise you could just be setting yourself up for drama's forever more.
At least you know he is not cheating,at least not with the opposite sex ;-)
I would not chase someone who has chosen to behave towards me in such a nasty fashion.
Doing so gives them massive control over any future relationship you may have with them.
Friendships should be built on mutual respect and understanding.