This isn't medical advice but:

What the poster said about Immodium, or Immodium A-D. It has Loperamide in it, which is an opioid, but because it doesn't cross the blood brain barrier, you won't get high.

It can be addictive though, like any opioid, so it's just to get you through the early jitters. Don't take it long term. You can get it at any grocery, walmart, drug store, etc. It's a diarrhea med. so look in that department at the store.

Also eat bananas for potassium, a good multivitamin, and drink plenty of water. Maybe with a "real lemon" packet in it. It's a little packet of lemon crystals for flavoring.

If it doesn't help or gets worse, go to the emergency room.

Good luck OP. Hang in there.