I have been dealing with severe anxiety for a few years now and it can be awful. But here's what happens to work for me. Distraction, deep breathing, a thing called tapping ( you can find videos on YouTube about it). Also being cold helps me for some reason. I don't know why but it does. Whether that's a cool shower, having a fan blow on me or drinking ice water. I've even gone outside and stood on my porch in the winter. Anyways, those are my go to things for it.