I think I may have figured it out.
I practiced again last night even though I was veeeery tired. I walked past Angus and thought, "I'll just play a couple of the tunes I need to work on most . . ." and picked him up and started to play. I got about 15-20 minutes in, which is better than nothing. Right?
Previous mindset went something like this: OK, practice. First of all, I'll warm up with a competition tune. Then I'll play around with tuning for 10 minutes or so. Then, since I need to work on endurance, I'll play all 40+ tunes that I know off by heart back-to-back in a set. Then, I have a few tunes that I'm especially concentrating on, so I'll play those about 6 times in a row each, without stopping in between . . . Looking at that lineup from before starting, it looks way too much like work so I never start at all. - Kind of like gardening. I see that garden filled with a bounteous harvest of weeds and I think, "Well, I have a couple minutes, I'll go pull some." But when I think of all the spiders hiding in those weeds, and I see I don't have my gloves and I can't remember where I put them last, I just go find something else to do.
Now, if I can just remember to put that attitude in my head every day when I head for the pipes . . . Just a couple of tunes, that's all . . . I'll do much better.