So this doesn't sound good (even for you, with your amazing record of fine orienteering despite all sorts of ailments). Have you had sciatica issues before. I have, but only briefly, so not much to offer in the way of suggestions.
This is the first time I have had this particular problem, and I suppose it is not actually sciatica, which would seem to affect the back of the leg, but certainly it is some kind of nerve impingement affecting the front of the leg. I'm going to try to find a doc on Monday to see if I can figure out what to do to calm it down and then get to the underlying causes of it and all the other symptoms.
I had something like that a few years ago. Pain down into my quad, rather unpleasant, especially sitting, and not at all clear what to do. And then in 2 or 3 weeks it just sort of faded away. Maybe you'll just be lucky.
Sounds like my problem of a number of years ago. Tried many things from ignoring to rest for a month or more and different PTs. Nothing worked till I found a PT that gave the several stretches for the piriformis and iliopsoas. Diligently doing those cleared it up over several weeks. Evidently the sciatic nerve works its way through the hip joint area and all those muscles which have a tendency to expand and impinge on the nerve. The pain can resolve in various parts of the leg or butt. For me, it was the butt and a tingling in my outer shin. The shin was the worrying part as the muscle gradually faded due lack of nerve, and I developed foot flop when running as the muscle was gone that restrains the forefoot landing. Once the nerve issue was fixed the shin has come back. Took over a year before I found the right PT expert. Good luck.
I spent about 15 minutes using my lacrosse ball to try to release the knot in my left glute. That seems to be where all the mischief comes from. Anyway, got it somewhat reduced in size and the symptoms diminished a bit, even if they are not gone. So I'll keep at it.
The description from PG describes exactly what I had earlier this summer. (I talked to you about it briefly at Hurd.) One annoying week of difficulty walking/sitting/sleeping, and then it slowly faded away all by itself over a week or two.
Hope you'll "just be lucky" too.