Welcome and nice work - hearing you're on day 18 already is super encouraging. It's those first few days that can really be tough, I notice that newcomers who are really struggling on Day 1 or Day 3 often give in to the temptations. By Day 18 you're definitely out of those woods....of course learning how to live a sober life is a huge task too, much more challenging (in a different way) than beating those first few days.
I'm glad you're feeling good - enjoy this happy moment and put it in your back pocket! Have a wonderful day!