First off, no guy is rejecting a guy because he's too skinny. You're most likely boring, personality sucks and offer nothing of value to them. But they aren't not hanging with you over your body type so forget that. Second, if you're skinny, in general, work out and eat more. It's not rocket science. An hour a day or every other day to workout and diet changes. Diet is most of it. As to the fear that you may be losing the best years of your life to get laid, get over it. It may very well be that you dont get laid in college. Guess what, you didnt prepare for it, havent worked on yourself, so I cant feel bad if you dont get those rewards. In life, you typically get what you work for. I disagree with advice like you deserve to get laid, because you havent worked on yourself to offer any reason for a girl to sleep with you. You're not enough. I think advice like you deserve a ten for just being yourself, is the worst thing. It's good to hear, but life doesnt work like that. If you wanted to become a millionaire, you dont become one by thinking you deserve to be one. You put in the work and start a business. If you wanted a Ferrari, you dont get one from thinking you deserve it, you get it from putting in the work and buying one. Same with women. What you receive from life is what you put into it.

If you want to sleep with women, you gotta workout, become interesting, learn shit and become an attractive person. There are no quick fixes. Learn how to make friends, learn how to improve your body, learn how to get women. It's a long road ahead of you if you're starting off like this. There are no quick fixes.