Hello
@Allotmemteer
Not everyone on here has had a good relationship with their Person With Dementia prior to their dementia diagnosis, and there are other people (like myself) who have lost the love they once had because of their behaviour, so you will find yourself in good company.
It sounds like you need more support. Assuming that you are in UK, then contact Social Services for a needs assessment and stress that it is urgent. Organisations such as Age UK, Crossroads/TuVida and MIND can often help with things like a befriending/companionship service (so you can have a bit of time out) or practical things like a Home Help and gardening service which can take a bit of pressure off you. I also find if helpful because OH was more tolerant of things like this and it gave me someone else to talk to. It is often a useful gateway into the PWD accepting carers.
If you can leave your mum for a short while, then try and get out of the house every day, even if its only for a sort walk.
If she is becoming extremely aggressive do please get back to your GP as there is medication which can help
xx