Advice Needed: Failed # Close on 6 Set - Live in BF

This is a long one but I need some help/consolation/advice. I can't say I'm a novice PUA, but I've learned a lot recently; a lot of reading and practicing.

So Halloween tonight. I went to a great house party here in Boston, didn't know any of the 4 tenants when I walked in, only knew a girl friend (Anchor) and the fact that her friend knew one of the tenants. I did everything right here except the close, I believe. I became the center of attention, worked the room, gained approval from her friends, gained approval from the tenants and other guys in the room, displayed value, negged her and the friends, didn't hit on her until a few attempts at the obstacles. I was working a 6 set with the subtle aid of my 3 girl friend anchors periodically throughout the night, which may have worked against me because every girl probably thought these 3 were all one of my targets too. They all either knew me or wanted to by the end of the night. I had so many ioi's via repeated eye contact, them bumping into me purposely, dancing next to me. Even the guys were introducing themselves to me. There were close to 100 people at this party. I approached the 3 of the 6 set initially indirectly while waiting in line for the bathroom after introducing myself to a tenant. She was 1 of the 3 but I focused on the other 2, negging and gaining acceptance. Periodically throughout the night I would approach the set and chat one of the obstacles up, even isolating while occasionally the target. I isolated the target late after many eye contact IOI's and playing cat & string and negging. She was a gorgeous b10 dressed as a farking cheetah. I playfully negged her outfit blah blah blah. I went to # close with the line my friends need a ride home (3 girls) who at this point were obviously my friends but when I approached the 6 set she was boxed in on the dance floor so we just caught eyes and I waved her over with a silent come here (the music was loud). The 5 obstacles huddled around her like a farking football team. I walked away about 10ft after this obviously went wrong (I immediately felt like an opposing player trying to listen in on the huddle, I didn't hang out but walked away casually) to one of my anchors until we caught eyes again. I went in again and got her away from the farking obstacles. She hit me with a veryyyy reluctant I have a boyfriend I live with. I was so shocked and being the farking PUA in training still 1/2 AFC said oh thats unfortunate I'm sorry. As we walked away, I grabbed my 3 anchors and went outside, I thought of a great way I could have # closed. I could've easily played it off with any line like oh I have a boyfriend I live with too or I have a girl I just wanted to get to know you and grab coffee (she lives in a city where my company has a big client, I frequent about once a week, Providence, an hr from Boston, could've used this to my advantage). Or gave her my card and told her to get in touch to chat, said something relevant about me and her and Providence to give up the digits or make her call me.

I need some advice and some lessons learned. Yeah it's a rejection but that means feedback and it just sucks to know the solution to my fark up. I guess it is true the most beautiful girls sometimes are the shyest. She clearly was veryyy shy and it took her 5 friends to remind her she had a bf. HELP! I'm a little pissed at myself because I know this could've been signed, sealed and delivered about 5 minutes too late. Any input from an intermediate, advanced or expert PUA would be appreciated.

keep your head up man