Struggling to move on.... worth a shot on here

[jay1991]

I was in a relationship with my ex for 3 and a half years, she was the first girl i have fallen in love with. She was amazing, the only girl ive been with that i can honestly say never gotten fed up of being in her company. We spent basically all our freetime with each other, i always thought of her whenever i wasnt with her and looked forward to seeing her again when we were apart like when i was at work. She was my best friend and we were planning on buying a house early 2015 together but this caused arguments too, she was at college studying and we fell out just before xmas when i was working away and in anger i told her to **** off and hung up on her, i gave in and phoned her and apologised 2 days later and we were back to normal, then two weeks after it she told me she thought i had finished with her and she had met another guy the day after we fell out and she says she doesnt know what she was thinking she just felt unloved and hated by everyone and he showed her attention so she went to his, they kissed and cuddled and she performed a sex act with her hand on him which is totally out of character for her and she straight after the sex act because she felt sick at what she had done. She says she had a break down and doesnt know why she did something so stupid. That absolutely broke my heart, even though i hated what she had done i was miserable without her so i took her back, i dumped all my friends during my relationship because i loved being with her so much id rather be with her instead of friends. I couldnt get it out my head though and everytime we had a lovely time together i would think she could be this perfect girl tonight then act the exact same with another man tommorrow and i always got upset and angry and brought it up time and time again and threw it in her face. We were on and off a while then she had enough and she ended it for good about 5 weeks ago. I think about her everyday, i cry every couple of days too thinking of her, ive still got no friends and basically just go to work then the gym everynight i dont do much else. ive been on dates with other girls since but i cant help think they’re nowhere near as good as my ex, even during sex with girls since then i still think of my ex. Its bad i know but i sometimes think of killing myself because i just wanna give up on my future because no matter what i do it wont be with her, however i dont think i would ever go through with suicide because it would devastate my mother but i do dwell on it sometimes and find myself day dreaming about it. I really dont know what to do, i have a good job with decent money, im not the worst looking guy on earth but i just cant move on. I’m miserable but pretend im not at work. Im so insecure and have such low self esteem since the girl i loved more than anything in the world was able to do that to me.