There are lots of in-the-moment anxiety busters.
What worked the best for me was quick intense exercise - so squats, jumping jacks, pushups, running in place, sit-ups. Just for a minute or two. Box breathing helps too, you can Google that one (sometimes called 4-7-8 breathing.) These get me focused back in my body at the moment and keep my thoughts from getting away from me.
You're in the first couple days, right? Maybe take it easy on the exercise though - might get your heart rate up too much. A walk outdoors is good. Intense exercise was really helpful for me after I made it through the initial detox period.
You're going to make it. Just remember it passes, you are healing. You can go to Emergency if it gets too bad - don't ignore actual physical distress.