One way to get over the fear is go and get yourself rejected a couple of times. After that, it won't bother you as much
That's a bit of a joke, but true nonetheless.
Another thing to remember is that EVERYBODY is intimitated by beautiful people. You say that they asume you have a g/f, etc (not sure what the etc is) and you work out. They are probably just as scared of you as you are of them.
One of the hardest things is to meet new people. Work from within your circle of friends. If there are no single women in your circle, then broaden the circle. Join a club. Become more social.
It's not easy, but it is SO worth the effort. The more you do it, the easier it'll get.
DB.