That’s the thing isn’t it, not only do you have to decline invites but also manage the feelings around it. Of course it makes you feel crap! It’s like youve put yourself in time out. But, you know the consequences, so id say make different plans with the family and forget the invite or tell yourself “another time”.
Unfortunately, giving up the addiction = changing your whole life, which means everything you know. That’s the reality of recovery and it’s a hard pill to swallow (no pun intended)