I am so depress?

its been about 2 months now my girlfriend let me, i havnt talk to her or anything .she broke up with me and told me she wasnt in love with me anymore. we dated few years and i am so sad right now i tought i could for get about her but i cant .i am really in love with her and i pray to god everynight 4 her to come back is there anything i can do? i think she might have aboyfriend cuz how could hearted can you be not to come back after 3 years dating. i wonder still if she even thinks of me or she even consider thinking of coming back. unestly i really love her and i dated other girls but i cant get over her cuz she was really the one i wanted, before the brake up i even talked about geting married to her and she say its still a littel soon so i said ok,so i dont know what her feelings even changed or not, or she got another boyfriend or not. a week after a brake up she send me an email saying that she cares about me and she want to be friends and i said i am sorry i cant do that.