I Took Bactrim About 7 1/2 Weeks Ago With No

I took Bactrim about 7 1/2 weeks ago with no problem, was given it again and have had a reaction to it. The Dr had me taking 2 Tablets twice daily for 2 days then 3 days taking 1 twice daily. I'm broke out in a rash and had vomiting Thursday night. Don't know whether to finish the dosage or not but can't stand the itching.