That diabetes 1.5 sounds very intereting. I have never heard of it. When reading about it, the symptoms of diabetes 2 caught my eye.
"symptoms of type 2 diabetes
Frequent infections may also be a sign of type 2 diabetes. In women, vaginal yeast infections are particularly common. Yeast infections can also occur on the skin and, in men, in the groin.

Other infections associated with undiagnosed type 2 diabetes include gum infections, urinary tract infections (particularly in women), slowly healing wounds with subsequent infections, and infections of the feet."



What is so interesting to me is when i did atkins for the first time I had almost all these symptoms. I lost 20lbs the first month then another 5 or 6 the second month. I stopped losing weight. Actually never lost more weight but continued w atkins over a year and suffered w/ all the above infections and horrible rashes. The first reactions didnt start right away, probably in my second month of atkins. First i had itchy redness all around my eyes. I thought it was my face cream. Then I got rashes on my armpits and back. I was in and out of the dermatolgists office all year. At the same time I got a yeast infection, then another. Then i started feeling exhausted. It went on for weeks. After i read an interview about a women who went in for a regular check up and found out she had stage 4 cancer, she mentioned her only symptom was feeling tired. So that got me into the Dr. who did a full battery of tests on me. He said i had a uti and parasites and that was why i was so tired. I took antibiotics for them both and felt less tired but i continued to get more bladder and yeast infections and the rashes got so bad i had to give up make up, deodorant, and soap, and severely cut back on the gym as they got worse with all of the above. My gums were sore and irritated. I didn't attribute any of this to the diet. As my weight and cholesterol and triglycerides levels were so good i thought the diet could do no wrong. Except the dermatologist gave me a list of foods to stop ingesting, which he said aggravates the skin. pork, diet drinks and coffee were on the list and which i consumed heavily on the diet. But cutting them out didnt stop the rashes.
The thing that was weird to me is thedr. said my blood sugar was almost at pre-diabetic levels. It wasn't so before the diet. Then i went off atkins because i was pregnant and when they tested my blood sugar i mentioned this Dr. He said there was no sign of amy problem and my levels were good. Also all my rashes went away. I stopped getting infections. It was almost a year before I could use make- up or deodarant without itchiness.
Anyway it seems extreme low carb dieting gives me symptoms of diabetes. I have upped my carbs to 75-100 daily and i feel much better. I am still not losing, but not gaining either.
I do plan to see a Dr. and go over all this

As you wrote, odd that you would get symptoms when you were eating LC and not, say when you were pregnant, which can push borderline blood sugar issues into gestational diabetes. No clue.
But sometimes a one off fasting BG test at the doctors misses on-going blood sugar problems you might see by taking BG at home, after eating, etc. as described before. Home meters aren't perfect, but over time, you can see a pattern. Kresser explains the three tests he would use to diagnose diabetes, including a five hour glucose tolerance test that your doctor could check, worth doing with the extreme thirst you have. http://chriskresser.com/when-your-“...-normal-part-2/