No offense intended, but isn’t that why shower rooms were invented? Waterproof the walls/floor with that cheap plastic stuff, curved edges on the walls for easy cleaning, plastic curtain on rails on the ceiling for blocking most of the water. Slope it down into the floor drain. No steps or doors. Is there really no safety net to get this sort of thing installed where you live? I would happily contribute a bit to a gofundme link for this, and I’m sure there’s plenty of others who would too. Example https://www.gofundme.com/f/helping-ric-live-safely-in-his-later-years?cp_src=m . Ideally social services should have grants for this sort of thing though. There may be one you can access depending on where you live, DM me and I’d happily put in a bit of research to help you find out if this is an option.
Edit: UK example https://www.gov.uk/disabled-facilities-grants/what-youll-get
That’s completely fair! Sorry, I underestimated the cost and the problem of getting permission as a renter. I looked into it properly and, although the plastic covering and curtain are cheap, constructing the drainage, sloped floor and waterproofing can still cost around £6,000–£8,500 here. If you’re comfortable saying which country or state you’re in, I’d still be happy to check whether there are any local grants, charities or tenant protections that might help. No need to give your precise location.