Is it normal I haven't had sex/dated in 4 years?

I don't think you're afraid of relationships. I think you're afraid to go with someone who doesn't meet up to your standards/expectations. You said that they weren't worth talking to because their intellect and interests didn't match yours. Thats sad. Maybe you should start giving people a little bit more of a chance. If I had a dollar for everytime I tell people, "Nobody's perfect", I think I would be a billionare by now.

You need to look beyond the "blemishes" that come with what makes humans human. Everyone is gonna have differences, and flaws. You just need to learn to accept them. Once you begin accepting them, you might very well begin to like them. And from my own experiences I've noticed that sometimes you think you have it all figured out about someone, until one day you realize that you were wrong. You could belive something about someone..."oh, they're into that... so they must be like that then..." but you could be wrong. They could turn around and surprise you. Sometimes it takes people time to open up, showing their true selves. It takes patience, but it's worth it. You might think you've seen it all, but you really haven't.