I am Type 2 Diabetic, diagnosed as Pre-Diabetic about 2009, diagnosed as Diabetic in 2012 but border-line, I was given Metformin & a Blood Testing kit so I could monitor at home.
Metformin was gradually increased to give good control but I did suffer from side effects. In 2017 I was in Hospital with a Urine Infection & Hospital stopped Metformin. 6 months later, with no medication I had lost over 3 stone, weight just gradually came off, I felt great & a lot fitter.
When it came to my Annual review my Diabetes readings were nearly off the scale, new medication, result my Diabetes is under control again although I have now been changed onto another newer drug. Only downside is the weight has just crept back on but I'm working on that, diet has never changed.
Beware of eating too much fruit because of natural sugars, 2 portions per day ie 1 portion is 1 banana, 1 apple, handful of grapes, 2 plums etc.
Lots of veg is encouraged apart from parsnips, beetroot & sweetcorn high are high in sugar. Potatoes & Sweet Potatoes don't count towards your 5 a day.
Good luck & I hope your GP has some answers, my Diabetic Nurses are brilliant. I had no symptoms before my diagnosis. Illness & Stress can affect Blood Sugars. Mine can suddenly drop or rise for no reason, I had a Hypo which ended up with 4 hours in the ED as Blood Sugars wouldn't rise (I live on my own & this happened late evening), I had eaten well all day including a healthy Dinner of meat, potatoes & lots of veg