Not quite as bad, but very similar situation here too. My husband is sometimes able to use the loo without any issues, but mostly he needs help finding the bathroom and the loo, and taking his trousers and pants down. Like you, my husband will go into the bathroom and forget why he’s gone there. I now wait outside and check if he’s done his business, though usually I can tell from the puddle on the floor. I go in after him to clear up. When he remembers to wash his hands the tap is always left on full. It is wearing. You have my sympathy, but no answers I’m afraid!