Housemate I'm living in threatening to walk in on me naked, what can I do in England ?

I am based in England, I currently live with my mum, her boyfriend and my 2 sisters. I am diagnosed with autism.I am 23

I do not have a talking relationship with my mums byfriend, and he's done many bad things in the past to me and im pretty sure a lot of them are illegal and that he should be charged with something but that's a whole other story.

I usually take showers first at my house somewhere around 21:00- 22:30, they usually take them later,they don't shower right after me or take a bath maybe they do it 30 minutes after They do not go anywhere in the evenings.

About a week ago they said that I take too long in the shower and that they will limit my time in it to 15 minutes. It takes me maybe 20-25-30 minutes to take a shower, I am just unable to do that, maybe the actual shower I can finish in 15 minutes actual shower in 15 minutes but it takes me a long time to dry myself.

I am autistic and very sensitive to just being wet which I know sounds weird, but I've got the need to dry out every beat of my body including thing like getting all the little water droplets between my toes, there's also no place for me to put my clothes on in the shower so i put them I a little bowl folded up and I have to be slow and careful so that my clothes don't touch the ground when I get the out of the bowl, it's hard to explain but I am very worried about any of my clothes touching anything there because I have two sisters who often don't wash their hands after using a toilet, I also have another problem where I wash my hands too many times a day causing my skin to fall off and become rugged and change my socks 3x times per day. Because of this it takes me a longer time to shower.

Recently he threatened to walk in on me even if I'm naked and get me out of there if I take too long, what can I do in this situation ?

Ideally I dont just want some kind of warning, I want him to be charged with something for this or if he walks in on me.