First I feel the need to highlight, you're asking this on an Internet community. A community that has a higher than average percentage of people who feel odd/out of place in society, those who flee to online social circles because real life one's reject them. So the general opinion you get here probably won't actually be representative of the general opinion of people overall.

That being said, Aspergers is Autism but at the high functioning side of the spectrum (People have started to try separating the two though, so I'm assuming your doctors didn't inform you of that part). So if you know what Autism is, try picturing it. Then imagine a less severe version, that's essentially Aspergers. Almost all the traits you see in autism such as sensitivity, pattern fixation, lack of ability to adapt, social difficulties, language issues, stimming etc. are all symptoms that can pop up in Aspergers. The only difference is they are either less severe, you have less of the symptoms, or there's both less symptoms and those symptoms are less severe.

Just felt that should get clarified, because you seemed unsure about it and if it may play a role in your difficulties and anxiety is life. Which most likely it is playing a role. Now that being said people without a diagnosis can also find people odd, or not socialize all the time. But they are common difficulties found among people with Autism.

As for your Halloween choice?
Just do what you want to do, the point of those halloween in parties is to have fun.
So if you want to go and think you'll have fun there then go, if you don't want to go than stay home and enjoy Halloween another way.