Sulfamethoxazole and suspicions

I am a 5'2'' tall asian 26 years old who had suspicions of an UTI and was givin this RX. After 7 days (on the 8th day OF a 10 day RX) I forgot to take the morning pill but broke out in a rash all over my body from neck to my knees. At first I thought it was a sun rash but it was even in areas where the sun didn't shine. After an hour I broke out to my ankles and on my face. After two hours began to itch and went to urgent care where they think I was allergic. I took another urine sample and still had irritation in the bladder.