Hi, I had a similar experience to you last September.
I had a blood test after going to the Doctors for other reasons and got called in to see a nurse to get the result - HbA1c 101
She tested urine and packed me off to hospital straight away due to ketone levels. Despite me feeling fine!
Hospital sent me home later that evening after a few tests that (I think) showed blood ketone levels OK.
Had all the symptoms (thirst, peeing a lot, and had lost weight) but didnt recognise what they meant.
The dietary advice from the Docs is not helpful. If I had not joined this forum, I would still be living with high BG levels and, whats worse is, I wouldn't know about it. The people on here have a knowledge based on experience of what does work and I am immensely grateful for the help to be had here.