Caveat is, after you've made attempts to interact. If you force yourself out of your comfort zone to attend social gatherings as an uber socially awkward and anxious person like me, there is absolutely no shame in just upping and leaving if you don't click with anyone and no one wants to talk to you despite your best efforts. Just getting there and trying is a serious accomplishment enough on its own. End on a high note, not a miserable one. Leaving doesn't mean you've failed, it just means you weren't feeling it.
Speaking from personal experience, it absolutely sucks to feel that social rejection, but I promise, you will feel infinitely better if you just head out the door vs forcing yourself to stay for longer and adopting a false persona to make people like you, or worse, ending up just sat in a corner until people finally start to filter out. You don't even have to bother with informing the host or organizer of your exit. Unless you're their closest friend and there's only like 5 other people there, I can almost guarantee it's absolutely no skin off their back.
It feels so much better and more natural to go to an event for yourself, for the drinks and food, for the music, than to go looking for social validation from others. It's tough to get to that point but the more stuff you make yourself go to, the easier it will become. I've gained so much confidence shedding that validation, but it's taken me several months of finally making myself interact with a lot of different groups and going out on the weekends. My go-to has been to find someone else who happens to be alone (there's always one or two) and strike up a conversation. 8 or 9 times out of 10 others will eventually join us, and it's much easier and less awkward than lingering around an existing group hoping I'll be noticed.
There are other times that have been absolute duds. I just went to a college alumni event at a bar where I left after 20 minutes because everyone was all grouped up already with old friends and super standoffish. Even then, I at least got a free drink and soft pretzel out of it so I don't consider it a total waste of a night.
tl;dr don't overthink it. It's okay to leave if you're just not feeling it.