Hi, TEdwards . . . more people feel yucky on antibiotics than do not from my personal experience.
Fatigue, feeling out of it and yucky in the stomach are usual side effects. Antibiotics destroy the good bacteria along with the bad in your stomach, so I would recommend for that part to try something like Phillips Colon Health or eating probiotic yogurt to help with that.
Whenever I have to run a course of antibiotics, I expect that I will just have to take it easy until I am done with them because of how they make me feel.
Hope you feel better soon!