I am 25, My sex life is kind of down the hill, I am kind of shy and can not approach to women easily. no girlfriend either for that reason, I masturbate a lot I would say couple times a week, the problem that I have is, I been with 3 girls so far, and it never worked out, whenever we end up having sex, I just couldn't have an erection, I don't know why, because I always have one, when I watch porn, or whatever, but when it comes to real, it just doesn't work. After the 3rd girl, I stopped trying, I turned down many girls, who wanted to have sex, because of this fear. I know it is not normal, but what to do?
I think you need to get yourself a girlfriend and take things slow. Not all women want sex on the first date, in fact in my experience, after meeting me they don't want sex full at all.
Viagra and other medications can help with that, but i would start by Googling "performance anxiety treatments" and seeing what you can find out on your own to help you get past this.