I've always been into sex, crazy sex, thoroughly enjoy it because I know what I want and what the other person wants. I've had plenty of one night stands, people I would just hook up with, and I know I'm exceptionally good at it. It's what makes it even more enjoyable, feeling like I control how good I can make them feel. 
I've been with my boyfriend for 3 years now. Just like most other people, when we first started hooking up it was intense, crazy, amazing. I'm the best he's ever had blah blah. My problem is, when I start developing feelings and actually get attached, sex feels like a whole other reality. Instead of feeling sexy, dominant and promiscuous, I start wondering why he's not looking at my face, why I'm not being kissed enough, and becoming highly aware that he'd be getting off to any girl that wasn't me either and all I am is someone that he can fuck. It's really hard to explain, but I just start feeling like it's not about ME, its about the sex. I start thinking about how he's just enjoying what he's doing because that's what he's into, not because it's solely what he wants to do to me. One time he suggested watching porn while we had sex to make it hotter and I got SO upset, why do you want to look at someone else being fucked instead of just being focused on me? Why would watching someone else naked be hotter for you? It's insane, I would be okay with something like that in a heartbeat with a hookup or someone I wasnt fully committed/attached to. I just can't handle the idea of him thinking about other women or finding them sexy instead of me. It makes me physically sick. 

Does anyone else experience this or anything similar? It's just a weird feeling for me and I can't really understand it. Thanks in advance. 