I am glad to hear that you are now beginning to see the BG levels drop now that you are on insulin.
With levels so high previously it is no surprise to hear that you were struggling to recover from other issues.
I was also a late starter of T1, but went into crisis rapidly so was picked up very quickly and went straight into insulin. It made me feel so much better, which I guess is not a surprise.
Which insulin have they put you on? Is it a quick acting one for meals?
Some are in this situation as their few remaining beta cells are trickling out enough to do the background work and they just need the Bolus to deal with the carbs at each meal.
I hope that you continue to feel better and that the levels continue to drop so that you can beget back in range.