Wow... well I just read your post and it seems like alot is going on. If you are having these feelings, there is probably a reason. It could be one of two reasons. He is cheating on you or you are very insecure with yourself and your relationship. No one can answer that for you. I do understand the feelings you are going through. I have been there in my life. I will share with you my opinion and how I dealt with my demons if you want. But only if you ask. I do not want to give you advice if you do not want it. I realize that in this forum I could, but my life and my experience does not pertain to anyone but myself. It worked for me.
Its not about getting what you want, its about wanting what you already have.