I took my first dose of Biaxin XL (1000mg) about 7 hours ago, for...

I took my first dose of Biaxin XL (1000mg) about 7 hours ago, for a ear/sinus infection. Approximately 4 hours ago, I felt severe stomach cramping, gas, jittery/shaking hands and havent been able to fall asleep. I made a huge dinner and that seemed to help a little, but I'm nervous about taking the next dose tomorrow. If it wasnt a Saturday, I would be calling my dr first thing in the morning to try something else. Antibiotics are supposed to help infections, not create a greater state of discomfort.