I went through this myself when I was in my early 20s. Not to scare you, but I technically had mono for almost 3 years. I was symptomatic for about a year and a half, and that time period was rough. However, after that point, I slowly started to feel better and my BGs steadily improved. My A1cs were not great during that period though, and I did require far more insulin. I also came down with other bugs more frequently, I guess because my immune system was compromised.
One thing that did help was spending a period of time on an all vegetable and fruit diet. I did some juicing along with consuming tons of raw veggies. That was the only thing that helped me turn the corner. My understanding is that there's just nothing medically that can be done to speed recovery. You just have to ride it out. I am so sorry you're going through that. I remember that period well and it was HARD.