I personally hate going out, especially when it is an "unstructured" social setting with no goals or conversational topic.
If I have something to do and something to say, it's much more pleasant. I really enjoyed playing in a blues band at various bars and nightclubs, because I always had something to do. I would arrive, set up, tune up, then I would play a set, go to the bar for a free drink, find a quite table alone and drink booze and smoke my pipe, then play the next set, rinse, repeat, then tear down, load the van, and ride home.
It was a very social setting but I rarely had that awkward "milling around" time. Even if I had nothing to do I could walk over and fiddle with the equipment so I would look busy. Sometimes people would approach me and ask questions or try to start a conversation, so i would talk for a short period of time then return to my "work". Somehow watching people sit around and socialize and "chat" and "hang out" in front of me made me feel like a social part of things even if I didn't have to personally interact with anybody.
My rambling doesn't really answer your question or give advice except to try to find a way to structure your "out time". Go with a concrete plan of playing exactly three games of pool or drinking 4 beers or something like that. Perhaps bring a briefcase or fancy cellphone so you can pretend to be busy and take your focus off all the people around you. Don't plan on being social, but if something comes up, it can be a pleasant surprise.