Yesterday when I struggled with the stairs I remember 4 years ago doing the same. I remembered how I tried to make the last flight so no neighbor would see me collapse, pushing myself really hard. Opened door, stumbled in, shut door and fell to the floor. Got up when I finally could, after 10 minutes or so.

So maybe I shouldn't freak out that I'm getting worse and worse. I must have improved a bit after that to get worse again, so hopefully I can finish off this spell in a few months and feel a little better. It's been a long round though, about 10 months this time, but still hopeful it can ease up.