Extended release metformin is usually tolerated if regular metformin causes diarrhea. You might try that. If still a problem, alpha lipoic acid, Berberine, and cinnamon extract capsules are supplements that help with insulin resistance. If you go to the Marks Daily Apple website and look at the success stories, you’ll see many people who reversed their type 2 diabetes with a Paleo diet.
My mom lost 30 lbs when she was eighty - pounds she had been trying to lose for decades - just by getting really strict about sugar. She used a glucometer for a few weeks to see what happened to her blood sugar after certain meals. White potatoes really made her blood sugar skyrocket. Her HgbA1C dropped from a sudden high of 8.4 to just 5.7 in just a few months with diet alone.