I really hope this is satire. ⬆️
OP, I’m sorry you’re in this situation, in all the ways. Looking at the timings, all this will have been overtaken by events. But unfortunately it seems like one of those things ‘If you have to explain, they won’t understand.’
Guilting someone into helping you - when they have made it abundantly clear they do not want to help you - never has a positive outcome. It just fuels resentment on all sides.
I am sorry that your twins have not grown up to be instinctively compassionate and thoughtful, especially towards the person who gave them life. I have twins myself and can only imagine how painful this is.
In your position, I would be practising consequence-based parenting. You can’t make them do the kind / helpful / thoughtful thing, but you can choose how much you decide to do with and for them, given how ill you have felt, and given their indifference to that, coupled with their refusal to assist. They are of course still your children, and also they are now adults. Boundaries innit.
So get onto practising relentless self-care. Prioritise feeling better and cutting yourself some freaking slack. Do whatever you need to do feel better and signpost clearly to your twins what the revised plans are.
Maybe let go of the need to express your disappointment to them - just mentally registering what happened and perhaps bringing it up at a later date when emotions and teeth have calmed down, and the festive season is over. Wishing you all the best and a speedy recovery. 💐