Def some good suggestions already posted here. I find breathing can sometimes make me freak out even more because ill feel my head fill up with air etc etc. And closing my eyes makes me dizzy. In addition though....if you can stomach standing up....stretch. extend both arms up...stretch. Put your hands on your hips and lean to one side then the other...stretch. Pull your legs up behind you, bend down then up slowly...stretch. Feel rhe tension in your muscles as you do it...those feelings are natural...they will ground you. Another good suggestion is to 'act normal.' Continue on with what you are doing, or start something new, stay occupied and bore those feelings away. Your body will catch up. Also, and this might sound random (because it is) but eating a peppermint or chewing gum, minty gum, helps me. And take a walk, look at things that are far off in the distance and wonder if you can make it that far. Get some sun, hug yourself. Do something silly when no one's looking. The dumber the better because it'll make you smile..and that's a start. Hope this advice helps.