Be yourself.  Changing for anyone is pointless and very short term.  If you do what you like and someone likes you for it, you have the basis for a long term relationship.
Try to be more social, Go outside, get rid of the monitor tan, bike or play soccer or something that you like to do that results in you meeting people of the opposite gender.   Then you already have something in common to talk about.  but the most important rule is BE YOURSELF!. 
You are awesome just the way you are, you just have to find one more person that sees that. I struggled with similar issues when I was younger, beating myself up emotionally for not being "popular", being a geek and not having the clique of people around me, but all it takes is 1 person, and you won't find them sitting in front of a monitor all day.