One smoke.. :/

I know I’m not supposed to
But I caved and had one vape smoke of nicotine. I’m not supposed to smoke for seven more days.
I’m not going to do it again, but I’m worried.
Have to see the doctor today for a follow up and I don’t think he’ll be able to see and I really just doubt one smoke is that severe

But I’m stressed

I’m kind of thinking of it like I’m already exposed to my bro secondhand smoke so it’s not like I’m totally nicotine free