please help I'm going to flip out

I posted last night about not being invited to my boyfriends formal. Well now I found out tickets are due today and had to say I want to come. He goes well I was gonna split a room with my friend!!! I don't want to spend a night with another guy. My bf and I are long distance and never get to spend time together why would I want someone else in the room. Ik it's cheaper but how do I get out of this situation?! I'm a 20 year old girl with my bf I would not feel comfortable with anyone else! Advice needed asap!!! I haven't even been formally invited by him or have him mention anything to me. So what am I supposed to do? Do I just say I'm going and I want my own room I will pay my half. I feel like he should have asked me to go before he goes to book a hotel room and all.