i felt this for long time, and still feel it sometimes, even though i have a girlfriend who loves me more than anyone else has ever loved me...
solution? connect to as many people as you can. by chance you are bound to find someone...
it always helps to know how people see you. ask questions from friends, or people you meet, ask how they perceive you. that will give you clues how to adjust yourself as a person. never take negative feedback as an insult, learn from it.
there is also a way to be more attractive, learn to have more self confidence. people like the people who know who they are. this may seem simple solution, but it works.