Yeah, I think the combination of not being able to realistically take breaks or travel is having the larger effect. My home setup would be fine if I had the room to put my desk somewhere not in my bedroom (it's arguably more comfortable than my office) but the routine of: roll out of bed, make coffee, desk, make lunch, desk, make dinner, couch/desk, desk, roll into bed sucks a lot.

I’ve just started nuking entire two-hour blocks of time out of the day, which is always pre-filled with back-to-back half hour crap meetings, so that I can go out on a bike trail. Most of the time people don’t seem to care, but on occasion when someone asks me why I wasn’t at their precious half-hour crap meeting, I respond that I had some kind of “carers” issue, and if there is anything relevant they need from me to send me an email about it, and I will reply with the info. Amazingly, that seems to effectively address whatever issue the crap half-hour meeting was for.

I'm fortunate to have a forest/river trail I can walk to. So long as the weather is halfway decent I do at least a mile or two (and can do up to about seven) every day. And there's basically never anyone on it.