Antibiotics after rhinoplasty: Bactrim seems to be giving me intense headaches.

Hello, I had a rhinoplasty round five weeks ago. The healing has been good, except I recently got a boil on my butt and was prescribed Bactrim. Bactrim seems to be giving me intense headaches especially at night. When I wake up in the morning, I find a small amount of blood in my nose which wasn’t there before the antibiotic. I believe the headaches are making me bleed from the pressure. What would I do? Also will this change the final result of my nose? Please help.