How do you cope if your parents have dementia?

[Floorcare]

My mum has just been diagnosed. But we have known for a long time now. I just find it so so difficult

It's not even bad yet, still able to look after herself. And you wouldn't immediately know, until you spent some time with her. But from a family point of view, she doesn't remember things about her children, her grandchildren, arrangements...anything really. So can't have meaningful conversations, there is no continuity. It changes your relationship doesn't it? Plus, she has become withdrawn and sullen...I think she realises the situation....which makes it even harder

Any advice appreciated, on how to adjust/spend time together

I'm sorry to hear about your mum. It is a really hard diagnosis and takes a while to adjust to. Things that make it easier for me are:
Asking open ended questions that there is no right answer to.
Recognising the changes in personality are the illness not her.
Trying not to correct her when she forgets.
Living in the moment - she might forget what she did bit she remembers how she felt.
Doing a dementia friends session.
Knowing when I need time off from it.
Getting good care in place.
And perhaps most important for me was knowing that I am grieving for my mum while she is still alive. That's the hardest part.

grieving for my mum while she is still alive. That's the hardest part

YES to this

MIL (87) has short term memory problems, and she's managing on her own at the moment. We've got her a very big clockvwith day & date to keep her oriented, SIL updates her calendar regularly, and she's fairly amenable to reminders. The heartbreaking part is having to help her find her way about our house on a minute to minute basis, and fitting the stairgate for her as well as DGS.

Just keep buggering on OP, and count every moment as precious.

Be kind to yourself - we've had more than a decade of small and bigger losses and I've grieved each one.
And grief for me has meant anger and frustration as well as tears and sadness.
A good support network helps - people you can vent to about the situation and about your mum.
I know the illness explains the behaviour in my rational mind, but it hurts when she forgets the really important stuff or says something tactless.