Aw hon, I feel for you. I spent the last month of last year, and the first six weeks of this year on antibiotics, due to a combination of strep, sinusitus and god knows what else. I took BiaxinXL for 2 months straight, and though it did help, I've still got the sinus infection. Guess who'll be going to the ENT in a few weeks to see about having them cleaned out and starting from scratch? It gets worse though, I live in Florida and my allergies SUCK big time. Rest until you leave, take sinus pills an hour before take off, and an hour before landing if you're flying. I hope you'll be feeling better.
Psst.. though if you're too sick to travel, call DRC to see if you can postpone the trip.. they're good with illness.