I’m on Nitrofurantoin and feeling so sick.

I have been on it since Monday and this is the fifth day. 100 mg twice a day. I will have completed them tonight. I had Cefalexin last week and according to the test this was sensitive along with Nitrofurantoin. Cefalexin appeared to work and by takingCyclizine with it I had no sicknessbut but when I stopped I had symptoms back again. However, Cyclizine didn’t help me with the Nitrofurantoin. I know you must always complete the course so I have persisted. This heatwave hasn’t helped but I have sipped water to keep fluids up and just hoped that all will be well when I finish these. I have felt so ill.
When I take the last one this evening it will stay in my system for 12 hours as it is modified. Today have been having niggles in the bottom of my bladder. I just hope it is the heat and not the infection. I don’t know what I will do if this doesn’t work. I’m 85 and have had a lot of infections but this improved when the doctor put me on vagirux about March time. I was so upset when one returned. Today I feel desperate as I’m so nauseous and not sure how things will turn out tomorrow.