Do you have a tendency to do this in most relationships? Particularly in close relationships? How is your relationship with your family (parents, siblings, etc.)?

My first thought is that you're afraid of making a commitment to him (or maybe anyone). Perhaps you saw tragedy in marriages, and fear those same things happening in your marriage. Maybe you let him close in your heart, and that fear pops up, causing you to freak out for no apparent reason. Like: I love you, leave me alone! Any of this sound familiar?

Talking these things out with a professional, a T, would be advised. Someone that you could be upfront and honest with. Someone that you could share very intimate thoughts and feelings with, and get preofessional assistance in working through.

Best wishes to you!