The aches have finally subsided today, and my tube of arnica cream has come in very useful too
I don't know how you tie yours, but in my dojo some (not all) people have a slightly different style. I had the same problem with my hakama falling down halfway through, but using this style makes it stay up no problem. Saves me a lot of embarrassment.
Basically, fold the front part down the inside, wrapping it over your belt. The front straps will have to be threaded through as well, but that's quickly done.
Generally, nobody notices any difference, save your pants don't show and you might not trip as much.
I do tuck the front of my hakama down inside my belt, and this has always helped a lot
I think it was a combination of the suwari-waza and my not remembering how tight I needed to tie it on in the first place that caused the problem
This is my second second-hand hakama (I've never owned a new one!) and is probably just a little too long for me, but it's in reasonable condition so I'll stick with it for now