This must be really hard for you. Youve got sense, you can see whats going on isnt good, and you love her anyway. It's one thing to spot a trap. Its quite another to stay out of it. You'd be surprised how many people go walking into something even though they know the consequences, and know they'll get hurt, because of love. Love does seem to over ride our ability to be sensible. You know this isnt right. You know she is hurting you. You know she is treating you badly.
So, here's the thing. Either you hang on til a time when she will realise how much you care, appreciate you, and see more of you (a time you can actually visualise, because this is when you go to uni, so it isnt in some impossible future) - your waiting will have paid off, you will have loved her no matter what, you will have hung onto the good thing in your life, there wont be any what if's. You might get very hurt because she might find someone in the meanwhile, and you might get bitter about what she's doing to you, so that you put yourself through agony, and when you can have her, realise you dont love her anymore because she was so mean, but this way, you make that decision, you stick by it, you honour it, you deal with the consequences, and you become a stronger person. If this is what you feel is right, this is what you should do. You cant do better than doing what seems right at the time, thats how humans work.
On the other hand you could end things now, to save yourself the possibilty of being mocked and pitied and treated with little respect by her and others who learn she is treating you like this. You'll escpae being used, you will be free to find someone else, she'll be the one who got dumped, she'll have to take the blow to her ego, not you. If you do this, its quite likely there will come a point when all the what if's surface, you miss her like crazy, and you feel you've made the wrong choice. Ending things with her is a much more active role than the passive one of simply waiting to see if things work out between you, and thus it takes a different kind of courage - this is the courage to act, like ripping away a sticking plaster in one go. The hurt will be intense, breifly, rather than strung out, but then you'll be free. This will mean accepting her loss. If you do this, you have to ready to move on from her and let her go, not immediately, but starting (however slowly) from the day you make this choice. There might not be someone as special again, but the odds are that you will find someone more special, someone who will treat you much better than this girl is treating you. You deserve a lot better, but it will be painful to take yourself out of this cycle. I appreciate this and wish you the best.