Break up advice?

Me and my girlfriend broke up a month ago, she was the dumper and it was for family reasons like she had problems at home! I was getting better, I was happier after the break up, I was getting on with my life, then she asked for my help and someone to talk to and I said okay because I did still care and I hated seeing her upset... After a few days she said she was getting better and wanted to remain friends, but all those feelings I'd put behind me when I was originally happy have all come back, it seems as each day goes by, she cares less and I care more because every day I think of ideas to say to her, things to try in some sad hope that I mighty get her back! I see guys comment on her photo saying she is perfect, and all I wanna do is tell them to back off but I can't because I have no say in this, each day I try to make it out like it's all a bad dream but then it hits me again and again and again! I keep telling myself to focus in my own life but all I do is think of hers and how I'm not part of it anymore:( I got so far, I was happy and getting on with my life, then I just fell again and I was right back to the start, I just need advice because it's driving me crazy, I can't stop thinking about her with someone else, how we used to talk and get on, then it's hits me that that's all gone...