Backstory for context first - I've lived in my (1st floor, very old - located on the town square town) flat for 5 years. I've had to put up with a toilet that leaked & didn't flush for 8 months. Recently had to wait roughly 5 months for the light in the bathroom to be fixed (after I first reported the problem), and the landlord knew I had resorted to plugging a bedside lamp into the hallway mains as a light source as there is no bathroom window and still took 2 months to send one of his workmen over after lecturing me on how dangerous it is. I've has multiple issues with my downstairs neighbours re. water leaks, which the landlord eventually fixed by sealing the bath. My son's bedroom can't be closed properly. I've had many issues with leaky kitchen taps, kitchen cupboard doors falling off. I slipped on the loose carpet on the hallway steps a year or so ago and fractured my arm, and ripped it up in a fit of frustration. The landlord has seen the missing carpet, and didn't pass comment. Everything is ancient (70's style kitchen), and I have to nag and prod and remind for the most basic, essential maintenance. I've noticed recently that an area of the kitchen floor feels spongy underfoot. I've also told the landlord that I'm convinced that the bathroom floor will collapse any day now due to the fan not working and multiple leaks that have happened since we've lived here. He doesn't give a toss, and does the absolute bare minimum (recently sent a farmer to fix the slow leak in the bathroom). There is damp and mold in both my bedroom and the bathroom. He has 2/3 workmen that he employs, all of which apologise profusely when they knock on the door, as they already know I won't have had any notice. I was napping on the sofa a few weeks ago as I wasn't well, and was woken by my 10 year old son telling me there was a man in our hallway - once again the landlord had let himself in without notice. He owns at least 20 properties that I know of (is currently building more), and has a well known reputation locally for being rubbish. His own workmen often mention how cheap/crap he is.

Unfortunately, I can't afford to just move. I'm a lone parent to 2 boys (10 & 15 years old) that are settled in school, and moving would mean I'd have to start over both with my work and (likely) the boys' school. The landlord is also aware that myself and boys are autistic and so are vulnerable, and I feel he uses that to his advantage.

What can I do? I'm near certain if I had an independent person come round to inspect, it would likely be declared unfit to inhabit. I like my flat, I just can't carry on for much longer with the state of disrepair :(

I live in the UK.

TL;DR My flat is in a state of gross disrepair, the landlord doesn't give a toss and takes months of my nagging for even essential maintenance. Is there an independent body I can contact for an inspection?