its not a lot of fun when everyone else is drunk... i hear ya! now, i have to admit, i do enjoy my family, whether there is drinking or not, and they have never tried to make me feel like i am somehow "less" because i didn't drink. but wow... i think your not drinking really hit that lady's nerve... and i suspect there is a reason for that and it has nothing to do with you!! perhaps you can socialize with the friends you do like on occassion, ask them over, don't provide alcohol, but maybe lunch and tea/soda/coffee?
i wouldn't worry about having said "shot shot shot"... but in the future, as someone who is working on sobriety, remember that when someone says "when", its best, perhaps, not to encourage them to drink anyway... even in the name of being a good sport.