I'm sorry to hear that. Here's a few suggestions...
1. What do you like to do? Can you do it with the kids? If so, do it. Go grocery shopping or something.
2. If that doesn't work try an online relaxation exercise.
If you can't do that, try to do the following.... sense what your feet feel like. Do they feel connected to the earth? Do they feel warm? Do they feel clamy? Then try the top of your feet. What do they feel like? Really try to feel it. Put your mind down there. Then try your legs.... go all the way up.
Another one is to try to listen to what's going on outside the room you are in. Don't ID the noise, but listen for bout 10 minutes. Then try to listen to what's going on inside the room. Same deal.
3. Buy a book,.... try A New Earth. I think you'd like it.
4. Exercise. Go for a run.
I know this is hard. But, try a few new things in the panicy state. Accept that it is a panic attack. It will pass. It always does. Don't try to escape it, that's what makes it linger. Accept it. I know this is anti what you want to do but it does help.
Excellent post and suggestions by Nasal!
I know it is hard....but remember that this is ALL anxiety.....your mind playing tricks on you...coming up with scary scenarios to frighten you (nice huh?) You are NOT dying. You are actually very much alive.....as proven by the extreme feelings of anxiety and panic you've got going on.
Hang in there....try some of the exercises that Nasal suggested....go for a walk...keep your mind as occupied as you can. It is the "down time" that is the worst for us anxiety sufferers. Nothing like a whole lot of spare time to dream up horrid fatal diseases, scenarios. Lovely I know!
Take Care...this will pass.