whysoskinny...
I've been off this thread for a couple weeks, but I'm back to put in another two cents.
The entire perspective of this forum has been on you cutting off this girl from your life, ending this seemingly endless cycle of wrong and getting yourself far, far away from her.
I still stand in this perspective, obviously, coming from the outside perspective; however, I can see that you have repeatedly tried to hang on, and for a reason. I know love is a powerful thing—the connections it builds are very strong. It'll take so much more than simply us saying "break it off" for you to demerit the time you have spent with her, and to cut off the hope that things will get better.
Here's what I think:
You need time.
I agree with several of the people here who say that there are certain problems that only you yourself can fix. She's been ignoring you. She apparently wants her space. She is saying that she "did nothing wrong" when, in your head, she obviously did.
You have to build a life that doesn't emphasize around her.
I can't stress that more. Even if you did lean into the advice to break up with her, or really, truly end things—you wouldn't be able to do so, at least, full-heartedly. I've said this before, but you HAVE to build up a support group. Reciprocate her actions and take some space and time for yourself. I know it feels horrible when you feel constantly sick and horrible and sad, but you have to realize that this space, right now, is what you need.
You want her respect? She won't be handing it to you where you are right now. You have to work on yourself until you can look in the mirror and say, "I'm better than this. I deserve to be happy and I will be happy."
When she notices that you're being successful by yourself and don't give a flying fuck about her successes - oh, here's the fucking kicker - it will feel good as fuck when she starts trying to interact with you more. When you begin to feel better about yourself, don't even bother giving her the time of day: let her know you are better than the way she treats you.
Bottom line: she runs to you, not the other way around.
Start by refusing to look at your phone. Temporarily block her from your contacts and delete snapchat from your phone, or whatever method it takes to sever your connection to her social group—her group doesn't matter.
You may believe that the feeling of jealously and curiosity inside of you of, "Oh no, what could she be doing?" and "Is she with another guy?" will intensify and, truth be told, they will.
You will probably feel like doing that is tortuous, but in all honesty it will be worth it. Realize that a lot of your trouble right now is with the anxiety of wondering what she is doing, and what your next move will be to gain back control.
Cut off all sources of worry and know that the only thing you can control right now is yourself.
There's no point in worrying on what she's doing; you will only succeed in demoralizing yourself and sending yourself back into a saddening spiral. Find those other people in your life right now and don't give a fuck about hers.
Do what I said and cut off the sources of worry
right now. Seriously. Stop reading right now and block her. Delete snapchat. Email. Whatever. Just. Get. Some. Distance.
Do not let this damage your campus experience more than it already has. Know that she is a problem that can be dealt with later—but work on yourself. Get some self-help books and, as I've said before, get the assistance on a psychiatrist if you think you're going to be struggling mentally. Don't be ashamed to turn to others for help.
Best of luck man. If you need more advice I'll be watching this thread occasionally. Do what I've told you. This will work out, I know you can get through it
Until then.