There's no hard rule that says if you wear a hair piece/wig that guys aren't going to like you. Personality goes a long way. Still, we can't ignore the fact that how you look is the only thing people have to go on when they first see you. If you look good with a wig, then wear it. Keep in mind that how your hair looks isn't the only determinant on beauty. There are ugly girls out there who have great hair and I wouldn't date them because they have great hair.
I'm sorry for your situation but do not despair. Not everyone is a vain asshole, but they are out there so don't be surprised. Personality really does go a long way. Don't shut yourself in your house. Get out there and meet people. Stay active. Give people a chance to discover the inside you. Case in point, If you were a fine chic with great hair but a super bitch, I'd have sex with you alright, but I wouldn't keep your ass around for long.
The condition of your hair isn't the sole determinant of your beauty. If you look good with a wig then wear it. Ever consider shaving your head bald? I've seen bald chics in magazines that I'd have no problem calling my girl. I shaved my head recently to see what I thought. At first I liked it, then not so much. Only because I still have a good amount of hair on my head. Maybe I'll shave it later in life when the rest falls out on top.
One other thing, I'm on anti-depressants and it really helps psychologically. I'm surprised I haven't read about anyone using anti-depressants to cope with their hair loss. I read these posts and I can hear the desperation in what they are writing. I think to myself how they should really see a doctor about getting on anti-depressants. They can make a world of difference in your life. There is no need to suffer the emotional trauma of dealing with hair loss. It can be tuff getting adjusted to anti-depressants but after a few weeks things will smooth out and you'll stop obsessing about your hair loss and get on with your life.