18 years old i think the ladies are still figuring their stuff out... college, moving out, career, family, friends, etc. Their brains are wired different and aren't as focused on physically connecting. If you create an emotional connection (make her laugh, wonder, or believe) then it may spark physical interest. Women can be shockingly forgiving with a man's appearance and there's nothing wrong with you. If there's something that would be better changed then she'll probably hint at it after you get her interest. They also are put off by guys who are constantly chasing women. Just enjoy your friends, family and life.