Okay so for a party, you should just chill and relax. Doesn't matter if you're ugly (you are beautiful no matter what). Everyone is there to have a good time. And for those guys, try to ignore them- give them a nice smile to show you don't give two fucks about them. And you need to crawl out of that little shell of yours and talk to some people while you are there, try to talk to the people that best resemble you. Just be yourself.