I had the same apprehensions about social situations during the first month or so, most of it was mental masturbation about the fact I wasn't drinking and everyone was looking at me etc.. As time has gone on, I am about six months without drinking, I have gotten over the paranoid feelings but I just get bored in some social situations or even when I am having fun I appear to be upset or pissed off. A few times recently my wife and close friends have pulled me aside in social situations to ask if I was "OK" because I looked upset even though I was actually having a good time.
I was at a lunch, for the past few years a bunch of us have gotten together to have lunch twice a year and we would get drunk and take the afternoon off and get nuts, and I was having a good time seeing people I haven't seem in a while and my brother kept asking if I was OK. I guess they were used to the totally care free drunk that I was.. We still had fun, I still told jokes like everyone else and BS stories and such but as the afternoon progressed and as people got drunker it guess I didn't and it appeared as if I wasn't having as much fun. It is a strange feeling that I think will continue to ease as more time goes by. It was cool however that all my friends toasted me for having stopped drinking, with oyster shooters of course, and many said they were proud and wish they could also, some were glad that I stopped because now they have a sober driver in the group.
It is normal to change when you stop taking mind altering substances in social situations.
Good luck