I requested wheelchair assistance on my last trip - I'd hoped not to have to do so, but a setback in my recovery put me into a similar situation to yours.

The endless corridors, waiting to board, the randomness of finding a vacant chair and then finding one that isn't painful (public seating is very poorly designed), and the way spine and sciatic pain become more pronounced when I am tired. I hadn't needed a chair on two previous flights this year and I hope not to need one on my next trip on Tuesday.

As DeafFlyer has said, your circumstances are exactly what these chairs are for. Last year I was totally dependent on a chair to get anywhere so I provided my own. With my last flight (because I am still weaning myself off from having to use one) I was grateful to have the opportunity to avail myself of wheelchair assistance.

I can't see how your situation is any different from mine.

Look after yourself!