Welcome to SR bymyself,
I agree with what everyone else has already said. If the wedding is a must, and it sounds like it is if you are in it, get through it and bail on the reception. If being around your family is a trigger for you rather it is because they are drinking or not, try to make plans for things to do where alcohol cannot be involved i.e. a movie, shopping at a mall etc.
If you are early in sobriety, the most important thing right now is YOU! Later, things will be easier but right now put all your energy into getting and/or staying sober. Those who love you will understand.
Best of luck, keep us posted
Liss