How can I rid myself of this terrible heartache?

My girlfriend recently broke up with me because she lost her feelings for me. Now I can't stop crying. We were togather for about a year and we would hang out all the time and go on dates every week or so. She is the first girl I had the courage to walk up to that I liked. I had a crush on her for about 3 years and it took me hours of telling myself that I could talk to her before I actualy talked to her. I'm really shy so that's why it was so hard to talk to her. She broke up with me about 5 months ago, I told her I understood that she didn't have feelings for me anymore and that I'd stop trying to be around her if she wanted. But I still like her and it just hurts so badly I can't stand it! How can I stop crying over this? Every time I see her or think about her I start crying uncontrollably and I feel so sad all the time now. There are some days I just stay in bed all day because it hurts so badly. I feel like I just want to die so I can stop feeling this terrible heartache, but I know that is something I would regret if I were around to see the result, so I'm not suicidal. I don't have any friends I can talk to or hang out with to keep my mind off of this, with me being shy and all I don't really have many friends, I can't really make any new friends now, I mean i'm really shy, now I'm always depressed, and I'm kind of lonely now. Most of my family is gone too, some of them are dead, others moved, and now I just live with my older sister who is always working, so I don't have any family to talk too either. I feel like my confidence in everything has been crushed. Why can't I stop crying or just get over this? I really miss her, but I'm not going to go after her because I'd rather her be happy and with someone else then be annoied with me. How can I get over this and stop crying?