Thank you for all your replies, it's a great help to me to get someone else's perspective. I was feeling like I was the one who was wrong because my mum says I am crazy and not being practical.
I don't usually live at home, but I will go back to my home city and stay with my mum every now and then. I'm now 30 and a working professional. My mum is 55.
It just upsets me to see her live like that. I went out to buy toilet paper (she said I wasted my money because it was going to be flushed away) and I got lots of fresh food delivered to the house. I tidied up one of the bedrooms so that it was liveable. The house has a smell of rubbish too, because she is too cheap to buy bin bags, and then she is too unmotivated to take the rubbish out. I have bought bin bags but she is too cheap to use those!!! She has a cupboard full of bags to 'keep'.
I mentioned that the house was a hazard, fire, vermin etc. She said I was being ridiculous because there were no flies, and why would there be flies in clothes?
She dared me to report her for stealing loo roll, she said 'report me then!' etc. We had arguments and she said I should just tell people that I was an orphan. She said it's nothing to do with you etc. I was being too 'unpractical' by expecting toilet roll.
I think with my mum's background: she was in an unhappy marriage with my dad. They divorced when I was 18, but they constantly rowed when I was little- about money and about how she was too good for him etc. she treated my dad like an idiot, and turned me and my sister against him etc. My dad wasn't a 'normal' dad either as he would only ever think about himself and didn't engage with us kids at all. He didn't know my middle name, he didn't know how old I was etc.
I definitely didn't have a normal childhood as I couldn't tell anyone where I lived, wasn't allowed to open the door incase it was the 'meter man' or 'TV licence man'. Couldn't have any friends at home as our house was dirty and a mess. One of my earliest memories when I got upset to be left alone in the house as a 4 year old at night with my newborn baby sister.
I don't think she will go to her GP as she doesn't feel like it is a problem. She thinks it's normal. She also thinks everything is temporary, and she will lead a fabulous life in the future one day, when she moves overseas and 'finds a rich boyfriend'. I try to gently remind her to prepare for the future in case Plan A doesn't work out.