This sounds intolerable. You must be a saint.
There seem to be three issues:
- Your mother's attitude towards you and your family. This has to change. Approaches you could not argue with as a child cannot be maintained now. There is quite a lot on the internet either the management related Eric Berne's transactional analysis around adult/parent/child or a lot on adult child. To be blunt the balance of power has shifted. You now have the power. You are looking after your mother. That does not mean that you should not be sensible and sensitive, but she is living in your hose. In many ways you need to be the adult, and she the child.
How to communicate this is a whole other question, but it is not untrodden territory. My mother does not live with me and is worried that I might abandon her as she feels my brother has done. So I have been able to point out that aspects of her behaviour (continuous criticism) is not acceptable.
Is there anyone she will listen to who might be able to explain to her that you are at breaking point and need some respect and privacy. Age UK, Carers Ass or Alzheimers Soc might be able to suggest approaches, mediation, or perhaps counselling for you to help you gain the assertiveness you need?
- Money. First are you getting all you can. Carers allowance for you. Attendance allowance for her. I would try Age UK or a very anonymous but detailed post on Talking Point (dont worry that your mum does not have Alzheimers - they operate a broad church) or Citizens advice. As a general principle your mother should be paying you full whack for food and board things. You can then choose whether to put some or all aside for future care care needs, eg to top up Local Authority provision. If it is in her bank account SS could spend it on basic rather than top up, so it is better under your control, especially if you are subsidising her now. I would be wary of claiming any Council Tax exemption as you want to keep any money she gives you, separate from your house.
- Housing. It does not sound as if your mother has any major impairment. However she may well in the future. The ideal might be some form of sheltered provision near you, so you could visit easily and oversee any growing care needs.
I think you probably need to sit down with your sister and agree a united front. Your sister ought to be supportive as you are carrying a big burden and are not proposing to land it on her - simply manage the burden and ensure it is sustainable into the longer term.
You should discuss:
Your mothers assets and income. Where is it held, who has access.
What are the alternatives in terms of housing, either now or later on. Abbeyfields, Almshouses, sheltered. Somewhere where she has a community but where care could be ramped up. What can she afford. Can your sister and you chip in a bit to buy a sheltered property (note be very careful with Churchill/McCarthy and Stone type retirement properties which can be very restrictive in terms of ramping up care - the GP or Vicar/priest will probably know local options.)
If you would need local authority/housing assn provision ask for a SS assessment and emphasise the damage to family life and the unsustainability. (And perhaps a way of getting across to your mother that she needs to modify her behaviour to help ensure the burden is reduced.)
You and you sister need to ensure that the Will is in order and that POAs are set up. If you can agree a common approach with your sister I think you may be better off having some form of joint POA given how entangled your current finances are. Or agreeing with the solicitor who draws up the POA, what you can reasonably seek in terms of compensation for room, board and time, so all is transparent and there is clear room between your and your mums finance - and no question that she has any rights to your house.
Once you have agreed the approach, or possible alternative approaches with your sister, you should both approach your mother in a well rehearsed way. (Sounds easy...) You are being reasonable. You dont plan to abandon her. However you cannot carry on subsidising her without POA or a Will or a clear understanding of her finance, and access should she have a health crisis. The past four years have been difficult and it is the time to look at alternatives which will guarantee her safety and care into the future.
The very fact of undertaking research and talking to local health professionals and organisations should help crystallize what you want to happen. You should also form a Plan B in case she refuses point blank. Harsh but she does not have the right to completely ignore your wants and needs whilst pursuing hers at your expense.
You should start by saying that she will be going to your sisters at Christmas. You need some family time together. She may rant and rage a bit but this should kick start a process whereby relationships shift.
It really does sound awful. Good luck.