Any thing which is more than normal level is not good for anyone.U should control everything within the range.Expectation from others is good but over expextation cause harm to yourself. You have to accept rhis things.Make ur friendship a sweet journy not a bitter one.

Evaluate youself why its happening with you?  Extreme possessiveness definitely violate someone's right to have some quality time for himself. Try to understand someone else's emotions . Give him some space.  Your such nature can be perceived as great problem by him in form of his future married life if he is not married yet. And if you have homosexual feeling for him then it will become the main reason for him to not be with you as he is not that type of person. I an not putting allegation on you. Just keeping a possibility ad in light of it you can discuss with any psychiatrist/ psychologist.