Prediabetes Insulin resistance

New member & thanks for some very informative threads, particularly RH.
My doctor told me I was insulin resistant. Did I misunderstand as it is usually associated with obesity?
At school I went from A student to D for dropout over 4 yrs. I fell 'asleep' mid morning & was exempted if I couldn't make it back from lunch. In my 30's I had a new lease of life when I discovered I was Celiac & obviously dairy allergic. That lower carb sufficed until I had to go grain free with Paleo 2 yrs ago. I am now 60. A pre-xmas party, vegetarian, selected Paleo except high carb, sent me extremely reactive hypoglycemic which I thought I understood from my 30's. At the doctor's my FBG was 5.8 on the day, to be expected on Paleo, so the doctor missed pre T2 diagnosis. Initially my FBG monitoring showed some 11's & 3's.Generally under 6 now getting toward 4's. I am working through fat adaption, [keto]. I have always been skinny, fit from work when not hypo.
So 2 questions; Have I misunderstood insulin resistance? Was I missed diagnosed diabetic & celiac never was part of the problem other than grains not being fit for consumption.

Thank you Brunneria. It is you & Kristin 251 that I was referring to in my first line.
In my 30's, when I asked for an Oral Blood Glucose Tolerance Test and presented a classic Hypo curve, it was basically, so what! It was then that I determined Diabetes was symptomatic. I am now coming to the conclusion that all so called diseases are symptomatic.
My blood results were very good, showing improvement over the previous 2 yrs. My inflammation markers & Triglyceride levels are minimal, thank goodness, in light of their end comments on atherosclerosis. Their query answered?
An answer for Tinnitus too, it really bugs me.
Wouldn't you like to have a memory like Joseph Kraft [95yo]. I have years of memory loss. Afraid he has wheat belly though.
I wondered why, these days, insulin was not measured. Glycated Haemoglobin [ a test over-viewing the previous several months] was 40 mmol/mol. Enough for Joe to diagnose T2. In Australia, HbA1c less than 43 is enough to 'exclude current diabetes'.
I have dodged many bullets, but been wounded a few times.
The explanation from my [good] doctor is that my muscle cells have limited insulin receptor sites, and my brain commandeers glucose when insulin is high, resulting in dead leg. My explanation of that; from having high blood sugar my cells protected themselves from too much glucose. From baby to teen, I ejected all my food both ends. I was allowed to eat eggnog, Fruit Loops and/with icecream. I was celiac.
I guess the last, difficult, month my body is rebuilding those cells & fat adapting enzymes. Insulin is doing what it should albeit, overloaded till it broke.
My favorite videos/blogs:
The best description I have seen of metabolic pathways, and diabetes too, is from Prof. Tim Noakes
10 more reasons why nobody should eat wheat at Rosemary Cottage Clinic.
And her take on ancestral teeth is easier to watch on Australia's Catalyst TV, [15 min.]
Thanks, Andrew