Welcome cncrsrvivr. If your endo gave you this diet plan and you follow it, why are you worried about getting enough protein? Maybe you should go back and ask the endo for more specific food items. Like Chris, I don't take meds either and I also follow a very low carbohydrate plan: lots of vegetables and salads but no corn, potatoes, rice or bread. I eat all sorts of meat, poultry and fish, cheese and nuts. Low carb plans are better for keeping blood sugar lower but you'd better consult with your doctor first.
Also, please look at some of our other threads that talk about metformin. Some members have discussed this medication and the best ways to help avoid some of those side effects.