I am going through a similar situation with a girl and im the ex boyfriend, if you wanna know my story you can read about it in break ups forum "Fatherless ex, need closure/opinions help"
Well what i think of your situation since i am in similar, I think the guy is insecure person, doesnt believe he can be loved, Hurt from previous experience, or just had a plain sad parent upbringing causing some sort of relationship pattern of destruction.
so many possibilities, but he is insecure, probably overhwhelmed by having you, although he enjoys your clingy actions and emotions it gives him security, but he is scarred and part of him is scared to commit and get hurt like happened in his ex.
In my case i am trying to give my ex reassurance and time to clear, if your chemistry is strong enough you will be together again.
these are just trials , every relationship has trials and scarred people have issues which restrain them from having normal relationships, so trials occur and break ups occur, and if things go right you will be together again and those previous trials will not matter as much.
everything happens for a reason, unless they totally are not into you, and truly have a reason to leave you, then do not rule out the future.
this seems too vague to be a reason to break up just like my situation.
keep the distance for awhile, if chemistry was strong then the heart will grow fonder as time passes.
take care.
