Help

Hi, I am 19 years old, female, 4.0 college student, good family, friends, everything. But ever since I graduated high school things just sort of went downhill for me. I had the typical high school story...dated the quarter back for a year and half...lost my virginity to him...he cheated several times and it literal tore me apart. This was about 2 years ago. I know I'm still not over it but I should be. We randomly hook up but last weekend I made a fool out of myself and he completely ignored me. I still think about him everyday. Anytime he talks to me I get sick to my stomach and last summer he added me on facebook because I had deleted him and for some reason I went into this really depressed mode. I think it's because I expect something from him and nothing ever happens, he could care less and just uses me, yet I still go running back. So last summer I began beating myself up about it and throwing up. I lost 10 pounds but gained it back and now I'm depressed about that. All I think about is food and I will binge and purge more often now. I don't know how to get out of this slump. It's really affecting me. Please help.