I was prescribed bactrim (sulfamethoxazole and trimethoprim) for 10 days for a severe acute bacterial sinusitis. i've never taken it before. is it strong and will it help?

Sinus infection: Bactrim (sulfamethoxazole and trimethoprim) is an antibiotic. If you have a sinus infection, it should help because it treats bacterial infections. If it doesn't help, a culture of your infection can help to pinpoint the right antibiotic. Besides antibiotics, a sinus infection can also be improved with saline nasal rinses, which I would highly encourage for you. Do them twice a day. Good luck.