Type 1 usually develops at a young age and is an autoimmune disorder from what I read. I believe excess protein plays a big part in autoimmune disorders.
To see if high-carb/low-fat will help your hyperglycemia, it's something you're just going to have to try. Fortunately with blood Sugar issues it's easy to monitor them with home glucose meters, so you'll be able to track the progress and know if it's working for you or not. What have your blood Sugar numbers been?
I had a similar experience being on a low-carb diet which means high-fat and being told to eat the other way to heal me and I thought it was crazy and I was scared to try, but glad I did start eating plant-based because within a week one of my major illnesses completely went away.
For some inspiration, here's this girl Kristina who had major hyperglycemia, fatigue, underweight, and had bad migraines among other health problems and healed it all by going on a high-fruit/low-fat diet: