You sound very similar to me. Like you, I have had T1D for 26+ years and have huge fluctuations in my insulin requirements. The key word there is insulin requirements. If I didn’t adjust my insulin pump settings on a regular (pretty much weekly) basis, sometimes by huge amounts (like a 50% increase or decrease), my blood sugar would be a rollercoaster during hormones and other times.
I’ve also found a very useful tool in reducing fluctuations for me is eating low-carb. This not only reduces daily fluctuations, but it also makes things like hormones much more clear because I’m more likely to notice that I’m suddenly running at 200 mg/dl since I’m not hitting that level on a daily basis after each meal.
Exercise is another very valuable tool, as long as it can be kept consistent and one learns to adjust their insulin around it to avoid too many highs and lows.
I have a very busy schedule work work, school, volunteering, other activities, and regular travel. I have an earthquake kit packed that doubles as my travel kit (I just take sub-kits out of the big kit, use them for travel, and then replace the supplies and return to my earthquake kit when I get home). I often fill pump cartridges when I have five spare minutes so that when my pump alarms I can just grab it and pop it in, as invariably those alarms go off when I’m heading out the door. After ordering something like pump supplies I’ll activate Siri and say, “Remind me to refill pump supplies in three months.” That way I don’t have to think about it. I put doctor appointments in my calendar (Google) as soon as I make them so that they’re also off my mind. I replace supplies used in my backpack when I get home so that I don’t forget to do so later. I bulk cook on weekends and re-heat meals on weeknights when I have no time or don’t feel like cooking. I bring all my own food for trips (I also have severe food allergies in addition to diabetes), and so prior to a trip I meal plan for each day and decide what I need to pack and buy once I get there.