I once had a boss who was half my age and younger than my daughters, but had an incredibly wise head on his shoulders for his age.
I was being badgered by an angry customer to change our way of working to suit her needs, so I took the problem to him.
I told him the promises/excuses I had already put forward and he stopped me mid-sentence. He told me to take a deep breath and tell the customer that what she wanted did not fit in with company policy/plans/structure and her demands would have to stop.
It would take courage, he said, but then offer a positive for a negative. So, in the OP's case "It's not convenient for you to call round so often but I would be happy to meet you once a fortnight at the local garden centre/coffee shop for an afternoon/morning of chat". If you are asked why, or for what reason, just stick to "not convenient" no need for you to explain yourself. It will be tough to begin with, but perhaps you could instigate the first coffee date away from home.
Sometimes, those with mental health issues cannot see the problem and need to be nudged in the right direction.