@Njegos
Air flow. Open a window/door
Vinegar then preventative paint
Dehumidifier (a good one)
You could replace the ceiling to 'start again'
Look into replacing it with something that you can wipe
Take the time everyday to do these things
Keep wet flannels and towels out of there
Get good mops and cloths to dry off surfaces after using the shower
Keep toilet seat down.
Also it actually takes very little time and water to effectively shower. Turn the shower on, wet body all over. Turn shower off, wash, rinse off. I can do it in one minute if not washing my hair.