BabeintheWoods,
IMO side effects sound worse than diabetes.
Using metformin may increase the risk of lactic acidosis, a rare but potentially fatal buildup of lactic acid in the blood. Since congestive heart failure, kidney impairment, and liver problems increase the risk of lactic acidosis, individuals with these conditions are advised against using metformin.
I know you are gluten free, but have you tried also going carb free?
From the research I have done, some people have a metabolism problem as it relates to carbs, gluten, wheat, which affects sugar levels, insulin production and control, triglycerides, HDL and LDL - they're all inter-related.
Perhaps that might be a better and healthier way to handle it, I don't know?
What do you think? Just trying to be helpful...