Most Helpful Girl
As the saying goes, "you're going to have to kiss many frogs before you meet your prince." I know this may sound cliche and overused, but be patient. Overall, be PICKY! Don't compromise your morals just to "get a man."
While you're still single, why don't you enjoy yourself? Go out with your friends. (Go to a movie! A concert! A comedy show! Even a play!) Meet new people. Find a hobby. (I don't know, try knitting? :P) Join a local organization or club at your school. You said you're Christian, are you part of a church group? Church groups and clubs are a great way to meet people and make friends that possibly have the same beliefs and caliber as you. You sound like a sweet person that I would like to be friends with, just that you need to open up and be a little more talkative at where you work/go to school/socialize. Plus, smile more often; you'll be more approachable that way. :)
And don't marry yourself...heh. XD. "Take yourself on dates"; if you can't spend time going out with your friends, then take yourself out and go to places on your own. Go do something that you like, and don't worry about being single at 20. There are plenty of people who are in the same boat you are.
I apologize that I was a bit lengthy, but good luck! :)