You can stock up on basics for minor injuries and perhaps some fish meds for certain illnesses, but I think it will be mostly “suck it up and keep moving” territory in a world of limited resources. People with any amount of medical training will be called upon for advice or assistance.
They’re pretty much all gone now but it used to be that folks in rural areas where there was little in the way of medical resources used home remedies. My grandmother was from a farm in a tiny village on the Gaspe Peninsula of Quebec. This is that wild and rugged chunk of land above New Brunswick where the St. Lawrence enters the ocean, It’s practically one of those “you can’t here here from there” places and so she learned certain things from her mother. Growing up we never went to a doctor unless we needed stitches, vaccinations, or surgery. Everything else she took care of with her home remedies, and I suspect she’d of done stitches too if my mother had let her. That knowledge base is gone, but I suspect there will some relearning along the way.