Hi
@Xigman and welcome (back) to the forums. We aren't allowed to diagnose here so I have to be a little careful what I say.
Normally sugar starts passing into the urine when your bg reaches 10 (ish) . So my
guess is that you start feeling more thirsty then. So I wonder if you are missing some highs with your two bg tests?
However UTIs can cause thirst (and infections also raise blood sugar) so it's also possible that your issues are a UTI and not a progression (yet) to diabetes.
Our nutritionist Emma Thornton details some of reasons why UTIs could be making you more thirsty, and what can be done to help.
www.avogel.co.uk
But on the other hand UTIs often occur when you run overly high blood sugars (speaking from personal experiences) so there is a bit of a chicken and egg situation here. And of course, it could be something else altogether that is causing your symptoms.
As you are familiar with diabetes you probably know to check for ketones. Overly high blood sugars for a month might make you thirsty, but shouldn't kill you, but if your insulin production has reduced to the point where you go into diabetic ketoacidosis then you need to go to hospital
immediately.
As regards the point you get your T3c diagnosis, I'd expect that that'll depend on your hba1c, which seems to be the main method for UK diagnoses, 48mmol/moll being the magical diabetic number. However, if you were in the US they'd reckon a fasting bg of 7 or more was diabetic? (Disclaimer, I'm not a doctor so could be wrong).
And this article is pretty good
Type 3c diabetes develops when your pancreas experiences damage, such as from chronic pancreatitis or cystic fibrosis.
(Uses US units so you need to divide the bg level by 18 - which again has 7mmol/L as the dividing point). But I wouldn't assume that they will put you on insulin straight away, there are other diabetes drugs they may try first.
Hopefully some T3c folk will be along soon who can give you some more knowledgeable advice.
But please consider seeing an emergency doctor or ringing 111 if your symptoms don't improve - a month could be a long time with those symptoms. And honestly, going now might be better. (Disclaimer again, not a doctor)