Type 2 Starting to feel tired again

Got diagnosed with type 2 diabetes was very tired hungry and weeing alot. Blood sugar was at 123 I am on 3 500 mg metformin a day. I have lost 4 stone in six months . Lead a much more healthy lifestyle. Blood sugar last check was 45 . Recently though have felt tired again even though I exercise and eat healthy. Have had two periods of feeling faint. Going to see doctor on next check up . But anyone ant advice?.