It's very difficult for me to do anything like this because I end up forgetting things so much - good old ADHD, not something funny pills alone can solve. Creating a routine and sticking to it works best for me, but I've never been unable to stick with it through more turbulent times. Everything is fine until something, say, an unexpected family visit or a worldwide pandemic, disrupts my everyday life and routine and then I just fall back to my old ways.
I feel you. Two things I've picked up that may be helpful:
First, as a sibling comment said, having a notebook always on hand is a huge help to me (I like Field Notes as they fit in my pockets and hold up to abuse well). Writing things down with a pen avoids all of the possible distractions of picking up your phone, and frees you from any structure imposed by task apps.
I write stuff down constantly--sometimes I write down tasks, random ideas, or just doodle. Later (ideally in the evening or first thing in the morning) I read my ramblings and organize the ones worth remembering into a more permanent place. Tasks go into a digital todo app, notes and ideas into OneNote, etc.
While this scribbling thoughts and organizing them later is barely a routine, its proved to be enough to get me through crazy times and back into a "real" routine.
The second thing: don't worry about your routine collapsing. It happens, it's natural. Accept it, write down the crazy business in your head, and slowly start building a new routine.
Something that helped me was instead of building a new routine, I went back to the old one but in stages. There are things I don't absolutely have to do, so they get tacked on the end and are optional so I can just skip them without much disruption in turbulence.
I've found that 'something' always at hand and with the absolute least cost of usage has helped enormously. Paper and Fisher pen, PalmPilot, Treo, now todo program on my phone.
Whatever is the quickest to get me to a list of reminders that I can choose from.
And I do best when I can sort those by effort required to complete. Refill cat food bowls, minimal effort, QED. Find contractor for back porch rework, not as simple. So I break it down and find a smaller step I can do and list that.
Even if I get knocked out of my list, I always have it to get back on track.
Tasks.org is my current tool, after trying many many others.
On my worst days I set a repeating alarm to get my attention and look at the list again. Sometimes exhaustion, sometimes lack of desire, but I have a wife and animals to provide for so one way or the other I make it happen.
