Now most people would think id say something short and witty here, but im not going to.
First off, she was with him for 6 weeks prior to telling you, sorry but if she loved you, she would not have been doing that in the first place. regardless of, she was confused, or didnt want to hurt you. She was just thinking of herself. I had an ex do the exact same to me a long time ago, we were together for 2 years and she left me to be with this vampire dude (dont ask). She told me she had been with him for 6 months but couldnt tell me. She lived in Blackpool and i live in London so the distance was an issue for her as she wanted someone close to her, but loved it when i was there, hence she could not tell me. She wanted to stay in contact too, however me being me, i couldnt do that. To not have contact is a good healer, you need to take the time away from something, to get your head around it and finally to heal the wounds it has left you. Thats what i did and now, we are friends again and ive been out with her and her current boyfriend many times. We all get on great and i dont even look back at what has happened. Granted it has taken 7 years to get to this, but its worth it. She is also pretty ugly now so it makes me thankful that we broke up otherwise i may still be with her. lol. However thats not my point here, we still get on great, which is what you want.
Right for you, like Jay has said, go out and do something different, take your mind off her and you need to call her and say that you do NOT want contact with her for a while. It is not fair on you for her to keep that control over you and not fair on her boyfriend. Basically she is keeping you hanging on just in case things dont work as she knows you will go right back to her.
I really feel for you dude as i know what you are going through, however please try to move on or you will be stuck in a rut for a very long time.
On another note - Jay - next tuesday for training, lets go to the gym