Current "Best Practices" is to schedule "Me Time" first.

This is =not= being selfish; it is self-care. "We can't pour from an empty cup."

However bad our day is, it is assuredly worse if we are tired, caffeine-deprived, hungry or frazzled. And if you get to be any of these things during a run-about day: Stop. Take care of yourself. Unleashing your "inner werewolf" ... not good for you or your Aunt, or for innocent bystanders.

If you have one of those planner thingies [1], now is the time to use it.

If not, grab a sheet of letter-size paper and draw an hours-by-days grid. Include addresses and phone numbers so you don't find yourself 'lost and late' when halfway 'there'.

Getting to your denturist in plenty of time will give you time to relax before the appointment.
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You already know that some tasks are time-flexible (routine groceries) and some are not (appointments, you're out of toilet paper, you are hosting the Big Party.)

Tell [2] your Aunt to write up her shopping list, and all the places she wants to get to (beauty salon, her doctor, ...) This will reduce double, triple or worse trips for forgotten items - or stops.

Estimate the in-store shopping time. Double, maybe triple that.

Oh - and "fold in" your shopping while she is doing hers.

If you need to wait for her (e. g. at beauty salon), bring a book or e-book. It's got to be better reading than that ten-year old issue of "Golf Digest" in the lobby. [3]

If you have a GPS, bring it inside and 'tell it' all your places, (Mine has a fading battery but runs fine powered by the car or my computer's USB cable.)

My GPS has an "optimize trip" button. This typically cuts my 'gadding-about' time and total travel by 1/3rd to 1/2. I'm free to override its suggestions, of course. ("No, no, no. The ATM ma$hine is the =first= stop.)
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Hope my ideas make your week go better than you are fearing.

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[1] I got a planner I like, for $1.38 at the "Dollar Store" ( $1.00 as in the store name + 25 cents inflation + 10+% tax ... sigh. Mine is the 2 facing pages/month kind (so it's not a brick), plus a bright pretty cover, which makes it harder for it to burrow under the piles on my desk.

[2] I said "tell", not ask. Tell here nicely of course.

[3] The single, marginally good thing the Meat Plague (covid) did for us was to clean out all the dead magazines from lobbies and waiting rooms ...