Yeah, as a long-time confirmed introvert, parties where I don't know anyone but the person who brought me can be pretty scary/boring. (That is, if I let them scare me to the point where I don't talk to anyone, they end up pretty boring.)
However, I have found that I can have a surprisingly enjoyable time at those if I just start talking to people who look interesting (and/or cute) without any purpose other than finding out what they're like and getting to know them better -- no hidden agendas. If they're not as interesting as they looked, or if they clearly aren't interested in anything I'm interested in, I excuse myself to get another drink or use the restroom, and find someone else to talk to. I recommend that course of action to Marten.
And a little anti-anxiety medication could be useful, but I don't know that he wants to start taking that right before a party. While it's easier to control the dosage than it is with alcohol, it can still take some time to find the right med and the right dosage for you, and the wrong dosage or med could actually make a stressful event even more stressful.
Edit:It's Henry V's speech to the troops during the siege of Harfleur, or so sayeth the Bard.
Bonus points to both of you.
This is where "training by doing" and willfully exposing yourself to scenarios outside of your comfort zone comes in.
Almost everyone is the same way. Once you realize that, it becomes much easier and more natural to ACTUALLY enjoy social occasions. Just have to get yourself out there.
Quoted for truth.
Concerning the "signs": Some people are better at "writing" them than "reading" them. If you don't think you're getting any signals, try giving them. Someone might pick up.
Oh, interesting idea. That honestly never occurred to me before. However, it probably helps a lot to have some idea what some of the signs ARE before trying to send any, or the results might be a lot like trying to speak to a deaf person with sign language when you don't actually know any. (And, of course, once you know what to look for, it becomes much easier to tell when someone else is sending them.)
I learned some of the basic non-verbal signs at a seminar on relationships I took in my mid-twenties, and I have to admit that this knowledge actually helped me get into my first-ever romantic relationship not very much later. (Yes, I was a rather late bloomer.)