Totally confused

My dr. told me that I was pre-diabetic. She said that my reading of 54 was "high normal" and put me on Metformin. I can't take it because it makes me so sick to my stomach. I've not had a glucose tolerance test since I was pregnant several years ago and had a different dr. I'm thinking she's just picking on me because I am overweight. I have Fibromyalgia and find getting through my everyday housework a challenge, nevermind exercising. However, I do go to an aqua aerobics class once a week. I'm not sure what to think and I certainly don't want to be poking myself all the time testing my blood if I don't need to be. Now since her diagnosis, my insurance has upped my copay and I can't exactly afford to go to the dr. now. Any ideas/comments/suggestions?