Ok I give up, I need help with an exgirlfriend?

It may be a long story but I need help or else...or else I don't know what I'm going to do.

Well I met her through my brother. She is one of his best friends. Well we went out and for the first month it was good. We sent text messages [ I even learned how to send one because of her] all day and always said how much we wanted each other to be there. We held hands, hugged, kissed [She was my first real kiss] and finally I told her I loved her, and she said she loved me too. [ Even though now we're broken up I still love her] however It slowly stopped as winter came closer.

It came to a time where in two weeks we held hands only twice and that was for about 15 seconds each time [No text messages were sent to me, but my brother talked to her all day. I didn't even get hugs some days].

After a while of that I asked her if she still felt the same way about me and she said she did. So I gave it another week, but with worse results, that being that we didn't even hold hands and she didn't really pay attention to me the times we were together.

Then she texts me saying that I was cheating on her! I did no such thing, I wouldn't even be caught being disloyal in my dreams. She went on saying that a very trust able person said I was doing all these things in which I wasn't and I will defend what I said to the grave.

[Note: this was the longest conversation we had in a long time so that's to give you and idea to see why I was so pissed. The first text in ages was not something of wanting to spend time together, but of lies]

In all of the mess of this I told her that we should put our relationship on hold, that we break up now and maybe [what I would love to happen] get back together at another time, unless she doesn't want to. She said ok, but I heard she was crying from my brother. I found out

that I hurt her really bad and I've never been so pissed off at myself. Even now, weeks later she cries when we get mentioned to be together by others who don't know about our split.

I really regret that I broke up with her. I thought it hurt to see her talk to my brother more than I. I thought it hurt to wish to be together but not be noticed by her. But once found out that I made her shed tears, that's a pain that hurts the most.

What can I do to fix things with her?