I think Tingly badger that you’ve had a pretty bad year thus far. Breaking up with your partner was horrible for you. Losing someone dear to you by their own hand is another cruel blow.
It does seem that by moving to be closer to your family that your mother could have been more thoughtful in terms of you coming to your uncles wake.
I don’t see that being able to walk a little in your own home means that you can walk in an unfamiliar place, even should you have access to some burly chaps to carry you safely up the steps. Nor do I think the absence of a disabled loo should mean you can use a non-disabled with help.
I’m with Cracowian in saying that your posts have been utterly rational and honest. I do wish everyone had wonderful mothers who look after their disabled children’s needs (whatever age the ‘child’ is). But there are many of us who do not have that. In her unthinking booking of the wake in a building to which you can’t gain access she’s excluded you.
Yes, I also see Chrissies point about your mother being older and also bereaved, but that in itself isn’t a good reason for ignoring your needs too.
I echo Carole and Cheerful Dragons comments about having a private wake, you, your uncle and whisky. And the rest of them can take a running jump.