Bactrim and postings

I don't wish this on anyone, but it's comforting to know I am not the only one. On Day 3 of taking Bactrim, developed a slight headache. The next morning, it was throbbing, especially when I bent down. The headache persisted, and was joined by body aches, sweating, and shivering. My doctor wants me to keep taking the drug, but after reading these postings, I'd much rather let the infection clear up on it own. Not sure if this is relevant, but I had an allergic reaction once to Amoxicillin (hives, rash). I cannot wait until this leaves my system.