-- Dr Dre
Dude, what I have to say may sound a little harsh, but....
If a girl ain't as into you as you are in her, you don't need her. As you're finding out, it's more trouble than it's worth. You deserve better.
A girl that has anything for you you will come to your house and ring doorbells, pound doors, peek into windows, and call your cell phone and listen to see if she can hear it ring through the door in the afternoon if you don't answer her calls that morning.
It ain't worth it to try chasing after a girl that won't make eye contact with you because she doesn't have the heart to tell you she ain't that hot for you...
(Believe me, when the situation is reversed and you have to cut a great girl loose, you'll understand that eye contact thing...)
That sounds hard until you realize how subjective it is. The fact that she doesn't wanna have your babies (at present) says NOTHING about you. Nothing whatsoever.
You also have to remember, there's very Few things dumber than a 18-20 year old girl. She probably doing whatever she's doing for all the wrong reasons anyway...
The sea is full of fish!! They aren't passive little mermaids either. They're predatory. They will get you....
On another note: Like others here have said, nothing kills love like anger and violence. You have to put yourself in her place a little to see the fear it causes. A man is bigger and stronger than a woman. She has no hope of winning a physical fight. She knows that deeply inside. Her whole psyche is wired differently because of that. Like a deer, she is highly attuned to threats to her person and is constantly aware of her vulnerability at a subconscious level. She's different than you in that way. The worst thing you can do is to trigger her threat mechanism. Fear is the opposite of love.
Take this to your grave:
No matter who you are, you can never force someone to love you. Love is a tiny little bird you have to hold very gently if you don't want to kill it.
Suggestions:
1. Accept that your heart's a little broke. This is the first step in getting past it. It happens to all humans.
2. Don't accept less than a girl who's crazy for you, and tells you over and over.
3. Put yourself around a bunch of women in the guise of some activity. School, sports, art, job, gym - whatever (except a bar!). Make yourself fair game in a no pressure environment .
It won't take long before one or another of them will have to have you so they can brag to their buddies....
Pretty soon, it's You who does the choosing. It's good to be clockin that grip!

Good Luck My Friend!