Am I Overthinking? Will I Fit In? Should I Just Not Worry?

Yeah, I'm just overthinking. It's no big deal. No big deal at all.

What am I even talking about? Well, I've been doing a little thinking (or a lot at some points) about meeting my boyfriend's friends. Now, usually this wouldn't be an issue I would even think about, but then again I've never been in this situation before. He's older than me, and pretty much all of his friends are therefore older than me as well. I already look younger than my own age, so that doesn't help me at all of course. I met his best friend, but that was before we were even dating or interested in each other at all. I met one of his friends at that concert, but we didn't really chat or anything because my friends were there too, and I didn't know what to say of course. Over this coming Thanksgiving break, another friend of my boyfriend is supposed to be having some type of shindig the night of Black Friday in the city, and of course the boyfriend wants me to come. At first, I thought it would be cool and fine to go (granted I can even stay out late...), but as I thought about it more, I became nervous. I know none of his friends. None of them. They're all of age, and I'm still freakin' 19. What if they decide they want to go to a bar or something midway through the night, and I can't go because not only am I underage but I also do not own a fake ID? Will I feel uncomfortable being around them since they'll all be drinking, and I won't? I mean, I've been in a room full of people drinking before and felt perfectly fine, but I usually knew at least 3-4 other people there. This time I will literally know one person, and I don't want to seem like the girlfriend who doesn't speak or is a bitch because I don't speak or is weird and doesn't fit in with everyone. I feel like they're all really "hip" people, and I'm just not "hip". I have a diverse set of friends, it's true, so maybe I'll get along better with some of his friends than others. I'm just causing myself unnecessary stress, that's all. If I can go to the party, everything will be fine. I'll just be myself as usual, but I don't want to revert to my shy self because I'm in a room full of strangers (which does happen). I just want everything to go well and for it not to look like I'm trying too hard or something like that. I don't think I would be thinking about this so much if he didn't say that he wants me to come and meet his friends. Can I bring a friend too, just as a back up person? Or what if they end up liking my friend more and basically hating me?

God, I'm being so juvenile right now. But I think this is a legit thing to slightly think/worry about. I mean, is it a sign when you don't fit in with your significant other's friends? Or is the real sign when their friends straight up don't like you at all?

I hate overthinking. I hate thinking about "fitting in" again. I had to worry about this last year when I wanted to leave this school and needed a reason to stay. I just don't know. If his friends don't like me- it happens. I'll have to accept it. Or maybe I'll just have to grow on them. Yeah, maybe that'll be it. They might find me weird and awkward at first, but then maybe they'll grow to like me and we'll all be hanging out and stuff like that. I'm hoping that's what will happen. I think too much. Way too much.