I'm a 32 year old male. This is probably the 5th time I've taken ...

It is not that unusual to get a rash from taking antibiotics. It took me about 3 specialists to be told that everyone taking antibiotics should take pro-biotics at the same time. The antibiotics destroy the good bacteria in your system as well as the bad, so the probiotics (found at health food stores)
restore the good bacteria. I don't understand why this fact is not more well known. I had a rash that wouldn't quit and no doctor or dermatologist could explain it, except the environmentalist physician I finally found.

Sorry to hear about your bad experience. Nothing is worse than trying to take something for relief only to end up feeling worse. I wanted to suggest that some of the symptoms you are having such as anal itch could be from taking to many antibiotics, killing off your healthy flora. You may have a candida yeast overgrowth in your system. Start taking probiotics to regain your bodies natural flora balance in your intestines. Yorgurt offers a tasty way to get the heathy probiotics in your system or taking acidolphilus capsules. This may help you find some relief..