ACE, your too young for this kinda heat...beleive me.
Your at the point 17/18/19 where people start their lives, going to college, working full time, even moving away from the comfortable place they grew up in. This brings alot of anxiety. It is not uncommon at all for people to feel like this at that time, to try and make things less serious before they go (physically or metaphysically).
You guys may have issues, but your both young, no need to argue, fight, or get mad...in the grand sceme of things, if you think about it, she probalby wont even be a part of your life 10 years from now.
The best thing to do is enjoy what you have, do what makes you happy, and have no regrets.
Girls will do this type of thing your whole life, want space but chat you up 24/7, say their not ready to date then date some other guy, etc...The only thing you can do is rise above that, lay down the way things are, and if it doesnt fly then move on.
For instance, she wants space...then give her just that. Dont be available 24/7, dont respond every time she calls or texts...go days without interacting if you got other stuff to do. If she mentions it, tell her your giving her the space she asked for.
You think she wants the space to date other guys, then date other girls if you want. She cant mad, as you put it she "broke up" with you...if she says anything tell her your not dating each other anymore so you dont see the problem.
You have to decide what you want from her, make it clear to her, and if she doesnt agree to it move on.