please do keep on at your gp, and if all else fails, go to a&e, you could always attend a different hospital a&e if you feel your current hospital are dismissing your symptoms.
I was told there was nothing at all wrong with me and it was all psychological right up until the day I was diagnosed. The day before I was diagnosed I was rushed to hospital via ambulance struggling to breath. They refused to do any tests and said it was due to anxiety.
Next day I ended up at another hospital (this one has a bigger resus area and intensive care unit) after collapsing in the street.
Following a simple finger prick test they discovered I was more than likely in dka, my blood sugar when sent to the lab was 49mmol and ketones were 5.5
My ph level was 6.9 and no one thought I would make it..
Basically what I’m trying to say is that because we trusted the medical professionals, I Almost died. You know your body best, keep fighting for answers, even if they find out Your are not diabetic (even though your readings are extremely high) they should still search for the reason you feel like this.
Please feel free to pm me if needed