Well, this is failure #3 in relation to falling behind in March. That's counting in terms of distinct failures in decisionmaking. If you're counting in terms of number of posts that haven't been on time since then it's more like failure #39. That's a big number!
So what happened? I think the simplest answer is that I was overoptimistic about catching up. At the time I recognised that it was going to be difficult, but I thought it would be an interesting challenge. That was true, but as it turns out the challenge was perhaps excessive. I was really endorsing a sort of trying hard mechanism where I would just muscle through the problem, but I didn't have a plausible mechanism for actually achieving that.
Ultimately, the outcome was that I would nearly catch up, but the effort of doing so was large and easily upset by minor problems such as getting stuck on some prototype. Even if I managed to catch up, that would often be exhausting enough that I would immediately fall behind the next day. Worst of all, I think it normalised the situation of being behind, to the point where it lost its power as a signal that something's wrong.
All of which is to say that I think there's a solution here, and it looks like the following: just be up to date. Clearly, not being up to date has significant costs and I don't think it makes sense to pay them anymore. However, I won't make the mistake of not having a plausible mechanism again. Today, I'm going to write as best I can to catch up (within a reasonable timebox so I don't get too exhausted by it) and whatever posts I can't complete I will replace with sketches of birds. But, one way or another, this is the last day that I will be behind.
I'm considering this my general-case solution for the problem of being significantly behind. Clearly my existing system of failure posts tends to work well for small slip-ups, but not for large ones. That needs a new system, and the new system is bird sketches.