Invited Friend from out of town to come to my college campus to party

I invited my close friend (I'll call her Emily) to my college campus to go to various parties. I consider Emily my best friend and she's told me I am hers. She has come down to my campus two weekends in a row. The first weekend was a lot of fun, we went to two separate parties, but I would feel she would rather talk to other people instead of hanging out with me. I didn't say anything to her about feeling this way during the first weekend. The second weekend she came down, we both drank and she wanted to go to this guys place on campus (she got his number from the party from the first weekend). We go to his place, there's two other guys, no one even acknowledges I'm there. I say hi to one of them but we don't talk much. I tell her I want to leave because I'm not having a good time and that I feel upset because no one acknowledged I was there. She tells them we're leaving and to to come with us. I didn't want them to come. We all end up walking to a house party on campus. Emily ends up telling the guys that I felt bad because they didn't say anything to me when I came in (besides the one guy I talked to). I told her beforehand not to mention it to them because it wasn't a big deal but she did it any way. I felt really embarrassed and started crying. I went to go use the bathroom and I said i wanted to go to sleep because i wasn't having a good time. she says that instead of coming with me back to my dorm, shes going to go back and party with people. I didn't want to leave her by herself because 1- shes drunk and 2- shouldn't you come back with me? Fast forward to the night, I ended up not going back to my dorm but instead gave the party another shot. After the party, Emily finds the same guys as before and talks to them and ends up wanting to go back to their place, i didn't want to go hang out with them. she asks me for my keys to get into my dorm room and i said no. she ended up coming back to my dorm with me. Next day she tells me that she is probably going to hang out with them and other people she met when she comes down here.

I feel weird because it seems like Im just being used as a means to meet other people. I've had other people do similar things so i am cautious about this. I tried talking to her about it because i dont like this feeling. she says she can't help shes social and that shes going to do what she wants to do whether i like it or not. i dont like the fact that i invited her (shes also been begging to come here) and now it seems im being left behind for the possibility of meeting new people. i should also mention Emily and I were friends in high school and I introduced her to my friend (call her Sara), and Emily and I ended up splitting up after an argument and she and Sara stayed friends. it makes me think back to that. sorry if parts of this are unclear, just looking for advice or anything really.