I can kind of relate to how you're feeling. I had (and still kinda do have) quite a few issues regarding sex after my ex broke up with me (I had never been in a relationship before then). I felt like I had been used, that I was just a toy to be played with in order to "lose it already." I still kinda feel that way, but I feel that I make more of a big deal out of it than my ex does, because to me, sex IS a big deal, but not in the sense that I need to have it often and with lots of different men (though I certainly desire it and enjoy it with the right man). For me, sex is a big deal in terms of emotion. That's why I could never sleep with a stranger. No one-night stands or casual sex for me.
However, sex is one of those things that just can't replace love and affection. Often people use it as a temporary fix for a long-term problem. If you could sleep with a woman who is practically a complete stranger on the first date, then you certainly can overcome your SA and be more confident around women. I don't deny that. But, overcoming SA and being more confident around the opposite sex takes time. Sex is one of those things that can be hollow, if there's no attraction or love (like I mentioned before, a quick fix). Love and affection, though, that takes a lot more.
I'm sorry that you felt like you got used. I don't feel used, but if I had been used, I wouldn't have taken it well, I imagine. I didn't know how to react afterwards because I had just done something very intimate that I'd been avoiding for years. I felt shocked and confused because I was so worried about everything and my performance was so full of weird mistakes that I felt like she hadn't experienced before.
My body didn't know how to react to this new feeling and new experience.
As for love and affection, I think that is something that is all dependent on whether you have chemistry with that other person. You may be right that chemistry should be developed over time, I'm really not sure. All I do know is that love is something that is just there between people. It's total confidence that you love that person.
I believe people in love should always be 100% comfortable with their partner. Silences should never be awkward. Staring at eachother should be comfortable. Talking should always flow naturally, nothing should ever have to be forced. That's my view of love anyway, even though I've never been it.
You're right that having sex with that woman isn't going to fix my problem long-term. I didn't expect it to. There were multiple reasons I did it. I had a situation where I felt I had to know what sex is like. I was tired of waking up every day not knowing what that experience feels like. It was killing me just not knowing.
Then there was the fear. I just went like 12 years of not being in a sure position of an opportunity to have sex alone with a woman. Who was to say that if I passed the opportunity i just had up that it wouldn't be another 12 years, then another 12. Before I knew it, I could have been 50 and still a virgin. I didn't want to be in that position. By then, tons of women are going to have been married for years and finding a partner my age would be even harder. My time would have been running out. I wanted to have sex before I die.
I agree with you when you say sex is emotional. After having it, I don't see how people can say it's not a big deal. When I hear that some people forget their partners that baffles me. There is nothing more intimate than being inside someone.