Most Helpful Guy
No, it's not unhealthy and nothing wrong with being attached to him either. Just relax a little, just make sure that your attachment doesn't turn into you getting clingy.
Being attached to someone is fine but being clingy is never fine.
There is no need for you to cry, and no need for you to break up.
Most Helpful Girl
Is this a problem with him? Are you smothering him? If so, then all you need to do is back up. Go hangout with your family or your friends. If you feel physically ill about it, take time to yourself and ask yourself why you are acting this way? Are you insecure? Do you think about him often in negative ways such as him being with other girls? I would stop, clear my head, and analyze what you are feeling first before making a decision you can potentially regret.