"Sister N has been in touch and offered to either visit mum on Sundays or help me with the myriad number of jobs that have built up." This comment makes me wonder whether you have been specific with your siblings about the help that you want? I am not excusing their lack of support, but it might be easier to get some assistance if you tell them exactly what needs to be done. Then they can choose from the list!
If you've got a stack of repairs to be done then you could ask for help with these. Perhaps the blokes would be happy mending hinges or painting, or carting stuff to the tip, or whatever, rather than the embarrassment of personal care or engaging in conversation with a relative who scares or bores them.
Hi Katrine - yes, I was thinking the same thing - that I have to be specific and that I ought to tailor my request to what they are going to be happy/comfortable to do. I feel like I am walking on eggshells all the time so will have to build up to anything too onerous. The old resentment kicks in though when I consider that I don't get that choice - and I have to spend my time organising them instead of being able to just leave them to it.
But - as already mentioned I am going to have to work a bit harder at letting that resentment go somehow. Can't expect miracles and at least I have had some offer of help which is very welcome!