Is it normal to feel like this?

I'm a guy and 24. I'm really shy and don't really approach women. I feel like no women would wan't me because I'm not attractive, I'm really skinny (tired to gain weight and work out but I can't seem to put on any muscle), and I'm super shy. And I kinda stopped trying after being rejected a couple of times in the past 4 years because I don't want to put women in a weird situation by asking them out since no one thinks of me in that way, only as a friend. Also its not fair for them to put up with someone like me when there are plenty of other nice guys who are confident and good looking. Is it normal to feel like this? Do shy guys find someone to spend their lives with?