What is wrong with me sexually?

So let me begin by saying that I'm 25 years old and sexually active with me finance who I have been with for 8 years. My sex life is not exciting at all, maybe twice a week or three times if I'm lucky. I'm constantly sexually excited. When I'm alone I can "touch myself" three times a day on average while watching adult videos. Here in lies my confusion. I'm into everything! !!!!!! I feel like I would literally have sex with anyone, man or woman, young or old and even crossdresser or transsexuals types turns me on. I dont understand why I am turned on by everything or why I am able to find something beautiful or sexually exciting in most people. I mean I have certain things I like depending on age and sex. For instance in a woman I pretty much could fantasize about any woman I meet but not the same for men. I can fantasize about men but only if they are really overweight or feminine or even ethnic and petite. I'm just really confused and this has been progressing over the years and I don't know what it means. Please help me.