i dont know if i can share my sad story here >< seeking for help..

i just broke up with my gf recently, we both had been together for about 5yrs+ and get along very well.  she suddenly just dont love me anymore and i keep to convince her to tell me why countlessly. she just said doesnt have feel anymore. she said she had thought aboutt it for past few months already, just that she don't dare to tell.. end up she admit to me and said ' i know this is cruel to say, but i don't love you like i did anymore. ' i'm guessing she had another guy behind, a guy who can teach her guitar ( my gf likes to play music instrument by the way, but sadly i got no talent in that, and also who sell his Myvi to her) , but she said we can still be best friends and she ask me to be strong and support me all the way. but how can i face her now? i felt cheated and my feeling for her still there.

But by just thinking my own gf suddenly just broke up with me and be with another guy is just too painful, and worst of all, we can only be best friends. I missed her and wanted to chat with her like we used to, but I stop myself when thinking that she already have another guy, and this hurts like hell.

I've seen some advised, and i committed myself to gym and try to make myself bz, but when this case pop into my mind, i just dont have the mood to continue my workout anymre.. I dont have much friends and most of them already have their own partners.

Can anyone teach me what to do? i'm feeling very depressed and down now. a lot of things just reminded me of our loving past. food, music, places, etc etc..