antibiotics making me miserable

I went to the hospital for some bleeding, I'm currently 14 weeks, everything came out okay but I had bacteria show up in my urine sample. I had no symptoms of a UTI but doc wanted me to take some meds. I'm allergic to sulfa, so he prescribed me macrobid. My insurance wouldn't cover it so I got a generic, Nitrofurantoin. I'm on day 3 and since I've started it I've been unbearable nauseas ALL DAY & NIGHT. I barely able to eat or drink anything. I've also had a terrible headache, and if I walk or stand for more than 15 minutes I feel like I'm going to pass out. I have to take this crap for 2 WEEKS. I take it with food and even have tried it with a glass of milk, nothing helps!! Any ideas on what I should do? Any way to curve this nausea?