Sober 6 years but drank 1 beer today

So I was sober for 6 years and 3 months until today were I took a sip of a beer and then I just decided I wanted my own. And I only drank that 1. But now I dont know what I will do. Like was it a one time thing? Can I just drink again now? Idk. Im freaking out but in a way I am also not. Any body has experience with one time not being able to control yourself so you had to become sober but then being able to drink after a while?????