I didn't walk Saturday (9/1), Sunday (9/2) or Monday (9/3), though Sunday we walked A LOT downtown on the way to the ballgame. I got too much sun, even though we sat in the shade, and was very achey Monday. It didn't help that we were very worried about one of our closest friends Sunday night and barely slept. (Long story I won't go into except to say it looks like this friend will be fine given time and rest.)
So today I got on the treadmill for the first time in September and did 30 minutes at 2 mph! I felt pretty good! I'm still really tired during the day and I cannot believe how swollen my legs have been lately. I have upped my protein and water intake and am hoping it may yet resolve.
I've also discovered that I need a new pair of walking shoes. 
Since late March, when I left rehab, I've gone from:
40 supervised minutes of aerobic exercise (recumbent stair and treadmill, 20 min each around 1.5 mph) 3 days a week
to
30 unsupervised minutes of treadmill at 2 mph 4 days a week.
Lessee...times 3 carry the 1...I was doing 120 minutes a week in rehab, and I'm back up to 120 minutes from 60 minutes a week when I first started getting serious about the treadmill at home. But I'm at a higher intensity now than I was at rehab, so from now on I'm making actual progress rather than maintaining. 