I took one adult dosage of Bactrim for a small persistent skin ra...

I took one adult dosage of Bactrim for a small persistent skin rash on my ankle. That dose has leveled me in a few hours. Chest pains, trouble breathing, body aches, loss of appetite and nausea. I went to GNC to get calcium and folic acid since I read calcium folinate is used to treat adverse reactions. They have helped some, but I still feel pretty bad. I can kick myself for not researching Bactrim first as I would have never taken a single dose. Russell