Confused/Scared

This is the first time I have told anybody this. Since I was 16 I have been curious about girls. I have had a long distance relationship with a girl and I really enjoyed it. It was nothing physical though. I don't only find women attractive I also like guys. In my later high school years I dated a couple of guys. My senior year I started dating my current boyfriend. We have been together for 5 years. He is my best friend, my everything. I was honest with him from the beginning. I told him I was attracted to women too, and he accepted it. He actually thought it was hot which bothered me. He has encouraged me to explore being physical with a woman, but I am scared. I'm scared I will like being with a woman more then a male. I'm mostly scared that I will disapoint everyone around me. 
I have lately been less sexually attracted to my boyfriend and more attracted to women. I feel so guilty! I don't know what to do. 
Please give me some advice