Got a LJBF a while back, have to get back

I've had this huge crush on a girl for 6 months. Very long story, so I will give detail in bullet points:

* may 11': met her online, hit it off instantly, didn't meet because I had serious health issues
* july 11': saw her IRL for first time coincidentally, totally fell for her. Couldn't get the nerve to talk to her
* she is friend's cousin, she later joined our social circle (student organization)
* couldn't get her out of my head, wrote to her on facebook. chatted for like three weeks, every day, only async msgs, no live chat
* september 11': at my birthday party, got her phone number, texted quite a lot.
* didn't ask her on a date, but I bought her a present for her birthday
* since then we've been seeing each for two weeks, watched movies at her and my place, walked, talked, ...
* last two days of this two weeks critical: day before last, I kissed her, she kissed back. we were at my place, 4h in the morning, lying on the couch. then she went home
* saw her next day, took her to dinner after work, went back to my place, kinda watched a movie, then I took her home. We didn't even kiss goodnight, she got kinda weird
* four days of silence, then she broke up with me. that was last day of october 11'
* since then, we see each other within our social circle almost every week
* tried to Win Her Back, we talk normally, but when we go partying, I can't do anything. She always hangs out early, then goes to dance with other men. She's had a few one night stands since then, which really devastated me. She was in LTR until summer 10'. Guy moved in with her even. She is 26, I'm 28.

I know my mistakes, I move way too slow, I'm not decisive enough. She's kind of artsy, I'm sporty/computer guy. We have lots of similar interests, can talk about anything. I get a weird vibe from her since LJBF. Any good advice on next steps is more then welcome... I really want her, need her. Tried other girls since October, but I can't really focus on them and tolerate them. I can't get her out of my mind. She's not all that good looking, a 6 or 7 I'd say, but her character and everything else about her is magical. I have no idea what else to do.

There's a few things you can do:

a) Flirt with other girls intentionally when you're around her. Get their numbers .etc Even though you've broken up, most girls still get jealous as they still see you as "Their" property.

b) Move on. Find another girl that takes your mind off her. Remember, "there's more fish in the sea".

c) Try to Get Her Back.
See the "Win Her Back" tag that was linked in your post. That's got some good info on it. When you interact with her, don't make her feel as if you want her back. Clear your mind of the fact you want to be with her and w/e.

Be spontaneous. "Hey, i'm bored. Wanna go get lunch?"

Hope it works out!
GL!