If I had to guess you are type 1 LADA. Often when someone develops autoimmune diabetes mellitus as an adult the destruction of the Beta cells is slow compared those who contracted in childhood.
Type 1 is an autoimmune disease whether developed in childhood or adulthood. At some point as you lose more insulin secreting Beta cells you will need exogenous insulin. That can be scary but you will learn the ins and outs to keep you alive and healthy.
I am no kind of T1DM, I’m a T2DM on an insulin pump. My journey took about 30 years to me needing insulin. I suspect yours will be shorter.
This earlier thread on books might be helpful.