[WARNING! Possibly boring thread! Read at your own risk]

We weren't separated due to fights and the such, so please think before you answer, ok? :/ (sorry if that sounds offensive)
Here are the details:

Me and (anonymous for no reason) were doing all right at the start of the year. She was diagnosed with depression, panic attacks, and fibromyalgia. I hadn't gone to see any mental health professionals even though I had it in the top of my to-do list because of short-term memory problems. So, she wanted to take a break to find mental stability after finding out that her problems didn't have perfect solutions and that she'll be coping with them for the rest of her life. I gave her the space, and while we weren't seeing each other publicly, her first ex took advantage of her mental instability by "sheltering" her, and we were through at mid-January... Less than two weeks later, he dumped her, and I dared not get close to the subject.

So, months after, I brought up some questions about how she was doing, and that I couldn't be happy without her, that I didn't care if during our break she saw shelter under someone else (plus it's a touchy subject), and the such. She still said she needed space, so I kept giving it to her. We used to talk through the phone all the time and stay up-to-date with whatever happened in our lives, even though we saw each other every day. We didn't get together again, and then stuff happened.

I thought I was doing good in college, so I didn't check up on my grades. This is COMPLETELY my fault for irresponsibility. I realized at the end of my second semester in college, that my grades would earn me a suspension. I made all the arrangements to move to a new college where I could start all over again (it was my first year in that one, so starting from zero was my favorite choice), and I evaded a suspension perfectly. Sad thing is... I left her at my last college... And I have no internet, cell phone, or car/money in which I could use to talk to her, so we're practically cut-off. We talk from time to time when I get on school computers, but it's not the same as face-to-face, or hearing her voice and laugh...

So, this is my problem: I promised her I wouldn't fall in love with anyone else (not like I can, since all I can think of is her whenever I think of love), but I'm scared someone might love her the way I could never do... And with lack of communication comes lack of trust, so what's preventing her from doing what she thinks I might be doing, which would be being with someone else? She told me that she had no interest in relationships last time the topic came up, because she feels she's volatile and might become aggressive towards everyone she comes close with (not violently, of course, just short tolerance... Althought she is amazing at hiding her frustration), so she practically gave me her word that she wouldn't be seeing anyone.

So, when I change back to the other college, I have no idea what I'll do to try to win her heart back. I can only hope that she still has some of the feelings she had for me, and that no one will take this chance at happiness from me... Truthfully, I hadn't been essentially "happy" until I met her (because of my own mental problems) and we started going out, and when we broke up, I couldn't really be as happy as before. She's the first person in the world I talked to about my problems in order to show her she's not alone, and I'm the first person in the world she talked about her problems to.

So... I'm sorry if this is stupid in and of itself, but: How can I alleviate some of this stress and fear? How can I assure myself that I will try my best to win her heart back, and possibly succeed? I don't want to be without her... Over 7 months after the breakup, and I still feel love only towards her...