Do I quietly just decline a drink,
That's probably the ticket.
I thought the magnetic poles of the planet would shift if I refused a drink. But, as time went by I realized that people didn't really care if I had a drink or not. All of the nervousness and expectation was on my part, it really was no issue for everyone else.
You don't have to say you're quitting, or anything about your choice.
I say no thank all the time now. But when I was around people who had seen me drink before, I would say I'd taken some painkillers, or had a cold coming on, an early yoga class, an early morning, etc. I didn't feel bad about the little white lies. It made me feel better and kept me sober.