I would suggest you read the book “Reversing Diabetes” by Dr. Neal Barnard. He recommends a vegetarian diet. I was diabetic, not PREdiabetic, taking Januvia, etc. My A1C was over 7.0. I made a major lifestyle change and became a vegetarian. I stopped all my meds except for 500 mg metformin for insurance. My last A1C was 5.6. It is not easy, you really need to be determined. You can do it if you make up your mind! You took the first step by asking for help.
I will just make one more point. If you don’t change your lifestyle right now, while you are still healthy, you will be FORCED to change your lifestyle as you will be sick!
If you need any help or info, please feel free to ask.