Hello @nikkicole ! The brain fog is horrible isn’t it. One thing that’s helped me is writing absolutely everything down- super tedious but it has helped. Essentially I have lots of shared reminders lists on my phone with my partner- one for Groceries, one for our daughter and one for general life stuff. Because they are shared he can see things that need done without me having to remember to ask him and rather than telling me we are low on cereal and me having to remember he can add it to our shared grocery list. I just wonder if your oldest has a smart phone and you could do the same? It’s just a way of trying to share the mental load for the household. I imagine your kids are looking for practical ways to help you. I tried a notebook at first but kept forgetting where I’d put it…. 
I am encouraged to read others comments that the brain fog improves 
Until then as wiser ladies have already said I’ll keep up with the walking and the water!