Need some help and advice

This girl and I were best friends for 5 years (both 23 now), and in the spring I made a move to tell her my true feelings for her that had arisen over the past year. She said she feels the same way. Now, I know she is a player and is constantly fooling around with plenty of guys. I assumed though, because she told me how much I mean to her and our history that things would be different.

We lived far apart and she had this one other guy in particular she went on dates with, but I was assured they were just fuck buddies, and nothing more ever. I was a little bugged by it, but I was told that it was purely sexual, and I was far away at the time. She ended up moving very close to me 2 months later.

She ended up seeing him every 3 weeks or so. At the same time, she told me that she had stronger feelings for me, I meant more, etc. She was becoming more distant, but I still took her on the best dates (her words), and tried everything I could to build our relationship. Cue to Sept. After a weekend with him, she ends it with me. She said that she doesn’t have any feelings for me anymore, they were never that strong in the first place, and has stronger feelings for this other guy. Also the fact that this other guy doesn’t care who else she dates/what she does with other guys means a lot.

I was (still am) real upset/angry about all this. She herself says that no one has treated her better or understands her better than me, and still wanted to be best friends.

But 2 weeks ago that guy flew to see her, and she told me she was completely over me and doesn’t even think about me anymore. On Sunday, I told her I couldn’t talk to her anymore because of how I felt. I am still in love with her reddit and I don’t know what to do. I work all day, go to the gym for 2 hours after, then play video games or go out with friends. She is still constantly on my mind. I have also deleted my facebook and her number when we first broke up.

I feel the urge to be with her, but I know that’s not going to happen. I want to move on and not waste anymore of my time and energy on her but I don’t know how.

tl;dr: 2 best friends who fell for each, girl leaves guy for fuck buddy, guy still has same feelings for her and wants to forget about girl.