I'm sorry you feel this way but in a way it's good because you may be able to change whatever is putting people off. Do you have a good friend or family member who would give you an honest opinion of what he/she thinks is creepy about your your appearance or personality traits. Women have makeovers ALL the time and so can men - take a look in the mirror and see what what needs polishing up - hair, teeth and clothes. You can also go to a salon and ask them to recommend a good hairstyle. Video tape yourself talking and play it back to see if there's anything that needs changing - sometimes we don't realize how we really look when we're interacting with people. It's also good to observe those people who seems to attract others. Start exercising (weight lifting) and make your body strong. Most of all you need to work on yourself confidence.
I also like what Lenny said about how one person's ugly is another person's Prince or like I would say "there's a cover for every pot". Perconally I would rather be wit ha no so attractive guy with a nice personality/good morals than be with a HOTTIE who has a bad personality. Women also like men with a sense of humor. Best of luck in discovering yourself and being the best you can be.