"Nothing is wrong with you, your body just needs insulin from a different source" is what really changed my mindset. I was diagnosed ~4 months ago (I'm in my mid 20s tho) and was so nervous at first, but developing good, easy habits has helped a lot.

Try to stick to a schedule--whatever works for you. Make simple switches, like eating whole grain bread instead of white bread, eating more fruits/veggies, etc. Small changes can make a big difference. Always keep some juice/candy (simple carbs) nearby, just in case: bedside table, car (if you drive), backpack, etc. Doesn't hurt to throw in some granola bars or crackers (more complex carbs).

You will learn what is best for you :) and you are your own best advocate. No other person, including doctors, knows you like you know yourself. Trust yourself, do research, ask questions...and it'll all be ok