a running theme I've seen is 1 "shyness" 2 "inability to let go of a past love" 3 "fear of being to ugly" and 4 "I just don't want it"
1: Shyness is easy to break, and it really just starts with changing up your routine. Instead of taking the left hall to get to class, take the right. Don't park in the section of the parking lot you always do, find a new spot. Always order the same thing at resturants, change it up. This will help break you of that, it worked for me and I didn't have anyone to tell me it would, I just assumed it would.
2: You have to let go, there's nothing there for you and holding on will just push you away from everyone. Life isn't a movie, a fun spastic girl isn't going to show up and totally make you forget the past love, it has to be done by you. (I have a long story here, but I will not share unless asked to)
3: No one is to ugly to be loved, and that is a fact. I recently attended a funeral (why does it start with 'fun' btw) and there was a woman there who, and I mean it, had no neck. It went from chest to chin, she wasnt strong or built, or fat, she just had no neck, and she had a husband. "But she's a woman, she has all the power" False. I've seen many men where I work who have wives, be it young or old, and many of them are "ugly" as you would describe them. Now not everyone will see it as so, and don't expect anyone to just fall in love with you, it's something that must be worked on, over months and even years.
4: You don't want it because you haven't experinced it. Love is something that will change who you are, what you do, who you hang out with. True love doesn't just change you physically but spiritually and emotionally. Love is something thats hard to describe. But I can best say it's like surving something that should've killed you, or a fresh breath of cold mountain air. You come out and that first breath, that deep inhale, that feeling you get from "being alive" is the feeling love spread through you every time you see that person you're in love with.