I know just what you mean Spuddle - we're all our parents' children and it's a peculiar relationship that we treasure and take for granted in equal measure so when something comes along to cause us to reassess the relationship it's a real jolt. But we 'muddle' through and find a way.
I'm in my 50s and if I'm honest resent that I now can't go to my parents for help as I always used to - but they gave me so much I am more than willing to give back as much as I can and it's another natural stage in life. At least I am able to support him.
But I also think we are allowed some selfishness - if you don't think of yourself and look after yourself then you will fold and be no good to man nor beast.
So, take your time with things. Your mum is still the mum and woman she was a few days or weeks ago, you just now have some insight into the future you didn't have then. Visit TP whenever you want, and stay away whenever you want - it's a wonderfully informative, friendly and comforting place to be.
But also find someone to have a natter with and blow off steam - you can't keep it all to yourself. So chat with a good friend or join a carers group, sometimes it's easier to talk to a knowledgeable 'stranger'. And remember that you are you and have every right to set time aside for whatever makes you content.
Now I'll just take a bit of my own good advice and get ready to go out with a friend who's lived through all this and is happy to talk about this, that and everything else. The vacuuming can wait.