Well, as far as the getting over someone, it just takes time. Think about other people and such.

And from what you are saying, it sounds like you are bi to me.

From the info there, I'd tend to lean toward bisexual, but in all honesty, you're the only one who can tell for sure. If you have the same feelings of love toward girls and guys, it's probably bisexual. Just because you don't like girly girls doesn't mean you don't like girls.
A buddy of mine can't stand the girly girls, but we'd still call him straight right?
Whether the girl is a princess or butch, she's still a girl, and if you like any girl in that way, you're at least bi or gay.
My advice: don't sweat it. Like who you like, and if it works out it works out, if it doesn't it doesn't. Nothing you can do about it.

First of all:
You're the only one who can figure out your sexuality. You may be interested in girls right now, but for all we know, this is a hormones acting up for you, and you're just experimenting (I have seen a lot of teenagers go through this then decide they're straight later on). It's up to you to decide if these feelings are solid. You may just be bisexual, though.

Second of all:
You cannot forcefully move on and get over somebody. In other words, you can't just think "K I'M OVER YOU" and bam! For most people, this just doesn't work.
Now, you can start off moping a little, but after that, you need to get your head out of the water. (hah... mop... water... haha... ha... ohshutup =[)

Don't spend time around her that is unnecessary. IE, don't go to the movies with her if you can, at all, avoid it, but don't skip a class she's also in. Reasonably spend some time apart from her.
Don't be rude to her about it, and don't make a point of it. Making yourself feel guilty on the topic of her is extremely counterproductive.

Don't be afraid to look at other people and flirt at a pace comfortable for you (honestly... if you push yourself into this, you'll make it worse...)

And when you find yourself thinking about her, distract yourself.

Even if you don't get over her entirely, just getting her off your mind so much will, at the very least, reduce the intensity of your feelings substantially.

the largest factor is just giving it time, though. It really takes time for you to let go of deep feelings.
Ever hurt yourself really bad (deep cut, broken bone, etc)? It took a long, long time to heal, but you let your body work, and it did heal and you have moved on from that to bigger and better papercuts.

Listen to your heart.