Ok, Metformin was my nemesis too! Not necessarily because of weight gain but because I could NOT get warm! Now I am by nature a very hot blooded person and am typically happy at about 65 to 68 degrees. So even my hubby was concerned because I had to stay covered and still shivered. My doctor didn't agree with me and wanted me to continue but I was so miserable! I took myself off the Metformin but stayed on the Glipizide and the chills stopped! My sugar is still high most of the time (usually around 200) but I am trying to work it out with diet.
I don't know why doctors don't understand that we know our own bodies best and if there is a direct correlation between taking a medication and the symptoms, well, there you have it!
Good luck. Diabetes is a monster! I can only imagine what my internal organs are turning into but since I feel I am doing my best, I am going to enjoy my life to best of my ability while I can.
I am so glad you found a doctor who listened to you. Just one question, did you ever take a diabetes education class? I did and they taught us how to read labels and it has helped. Might that be an option?