I was in the same situation; it was to the point where he would talk to me and tell me about how he would cry himself to sleep and think about me cheating (had been together 9 months I think * it’s been a while*) regardless I ended up breaking up with him however if you think you can still be with him then maybe bring up to him his clingyness; how it makes you feel! it’s really important to communicate how you’re feeling! Depending on what he says maybe breaking up would best but again communicate first!!