For me there's definitely 100% a trust component for me, and that's not just where sexual relationships are concerned. I am generally terrified of being emotionally vulnerable, especially to women, which is probably why the biggest crushes I've ever had have all been on girls that I had been friendly with first and knew or at least felt that I could trust. For example, there was a girl I used to work with who I got very close to. That started when I had commented to a friend and coworker outside of work that I thought this girl was "pretty much a smokeshow". He in turn ended up telling her, the two of us started flirting on and off, and we became pretty close friends. Only girl I've ever been around who could get me turned on just by holding my hand and looking at me a certain way. I never did end up sleeping with her - I felt that since we were living in the same dorm at school, had a lot of the same friends, and worked together, any potential falling out or awkwardness would be really really messy. Sadly after we graduated we kind of stopped talking to each other. That probably had a lot to do with me being an asshole and only sending text messages when I had been drinking and was looking to get laid.
The flip side of those instances would be the three one night stands I've had in college. I am not comfortable with those at all and often times feel guilty afterwards that I didn't try to get to know the girl better or spend more time with her. If I know the interest is there though and the woman is open to sleeping with me, I will take advantage. A common thing with all three was that I had friends tell me "So and so is interested in you, so if you want to make a move you're all clear". It's funny, now that I say that I feel like one of the reasons I don't have sex is because I feel like I need permission to approach women, otherwise I'd be bothering or creeping out the person I was trying to sleep with.
The first girl in that occasion was absolutely mind blowing, and we didn't even sleep together. I tried to see if she wanted to hang out the day after, but I think I was maybe too clingy and she told me she wasn't really interested and didn't "sleep around outside of relationships". I had a class with her the next semester, and found her personality to be extremely grating, so I guess that worked out in the long run.
The second girl used to hang out a lot with the same group of people I was friends with. My buddy had asked her one day if she'd ever hook up with me (sounds very middle school, no?) and she basically just said "Sure!". She was up for a party, and all I did was have casual conversation with her, just with more body contact, arm around the waist type stuff. Later that night we went out for a walk, fooled around a bit, and then kept fooling around back at my dorm. Afterwards it was a little weird between us, but we were still friendly. I felt like I didn't really perform all that well though, so I never tried to initiate that again.
Third time was a girl I had met that afternoon who literally said in front of like five people that she'd love to sleep with me. I thought she was joking until she leaned over and whispered "You should really consider taking me up on that". I did, and I regret to this day that I didn't stay in touch with her, but at the time I was staying at my parents house and my mom was freaking out wondering where I was at 4:30 AM, so right after the deed was done I left my friends house and went directly home. I really do regret not pursuing that one. She was a really sweet girl, but oh well.
Then I have my friends, who have been my absolute best friends since we were in Elementary school together. I have shared my entire life with them including everything that happened to me in the past. They're all supportive of my situation as much as they can be, though they all admit they can't really fully understand it because they have no context to compare.
I have questioned my sexual identity in the past, and even though everybody I know (including one of my gay friends), both of my therapists, and ultimately myself believe that I'm straight, the fact that I have such a hard time being sexual now, in addition to having been through what I went through in the past, makes me question. This most recent bout was two fold. I was out drinking one night and commented on how I hadn't had sex in three years. One of my friends off handedly said "I would have died by now. Are you sure you're not gay?" While he was just giving me shit, the thought kind of bothered me, but I let it slide. Then a few months later I had an opportunity to date a girl who was bartending at a restaurant I live near, but I didn't know how best to approach, totally flubbed the whole thing, and then started thinking "Maybe you didn't pursue that because you don't really care, which must mean that you like guys instead". That was literally it. I know that sounds ridiculous, but the simple fact that I can't disprove that and then move on kind of keeps me stuck. I try some strategies, like a meteor hitting the earth. It's not likely to happen, but if it did, there wouldn't be anything I could do about it, so why worry? Using the same logic, I don't think I'm really gay, but if I suddenly fell in love with another guy one day, I don't suppose there's anything that I could do about that. You love who you love, right? So why worry? Still, the fact that I feel bothered by it decreases my sex drive even more because I'm so paranoid about it, and then I've found that even when I am having sex with girls I'm not present because I'm trying to think about if I'm really enjoying myself, am I performing well, am I making sure she gets off, etc.
To pare that down - I am afraid to approach women because I feel like I'm bothering them, I have major trust issues that effect how I relate to them (I can't just pull chicks at the bar), and I have TERRIBLE self esteem and confidence. EMDR for the most part did help me a lot, but now I am trying to pursue CBT to try to stop a lot of my negative thought processes and hopefully improve my self esteem and all that other stuff in the meantime.