Originally Posted by
Jin
Socialise with him more just one to one,
it sounds like his clingy-ness is because he doesn't want to feel apart or distant from you especially after you rejected him which is what probably has occurred due to the awkward elements of it.
Your desperate need to get away from him only makes him feel more at a distant from you so he will cling on tighter. So by socialising with him one to one he will let off eventually
When I say socialise I don't mean wait for him to call you, I mean you need to arrange it with him yourself. Not just say yes to things when he asks. That way he will know that you two are still fairly close.
After a while socialise with a group of people and everything should return back to normal.