My son was diagnosed at the end of April, and he had some frequent adjustments to his doses, but his levels weren’t as high and he’s just 11. I suspect that you’re doing just what you should, so don’t get too down. Remember, your glucose levels didn’t jump to 600 in a day, and they’re not going to make it back to your target range (consistently) that fast.
As you improve your carb counting and figure out what your ratios need to be, your sugars will be a lot more consistent. Asking questions and getting the education to help you manage your diabetes is paramount to success.
I’m not sure how many people are dealing with this for the first time in your age range, but I’m guessing that it’s not a lot, so turning to this forum is probably a good thing for support. Feel free to ask your questions, as my handle says, I’m an ICU nurse and see people in DKA every week. Hopefully you’re feeling better at least.