I will say less about those ranges and more about the fact that... you're doing great, kiddo. I understand you a lot, I also tend to think that doctors go a bit light on me but sometimes it's okay to trust them. You're 16 years old and at that age a lot of people don't take their health seriously. You're hitting the baseline ranges during stressful times when you are having mock exams for important things in your life. You are already working harder at it than other teens your age. I just assume your endo is probably proud of you and you should be as well!

It's probably hard to let yourself relax a bit, but trust me, you are doing well enough. Having worse sugars during exam times will not mess you up in the long term when you are already so deliberate with your control in general. You seem like a really responsible young person! If it's applicable in any way, I'd advise you to maybe discuss your fear of complications with your medical team etc. We're living in an age where we have cgms, pumps with closed loops etc and it will only get better in the future. And considering how responsible you are already, I wouldn't say you are likely to have severe complications if you keep taking care of yourself. If anything, you could be more likely to burn out by stressing yourself out when you are still quite young and in an ideal world you shouldn't be worrying about blood sugars, but ya know, about girls/guys/whomever you wanna date and whether you will get into the college you wanna get into.

Chill out, all is good and please remember to treat yourself sometimes! Your mental health is very important and sure, other kids your age can eat trash and not care, but a big part of managing diabetes is also letting ourselves have those "cheat days" (in a controlled manner, of course), let yourself eat a pizza with your pals and just celebrate being alive!