Sorry to hear what you’re going through. I’m hesitant to advise because my situation is different. My son has an indolent form of Hodgkins which will require long term monitoring and possible further treatment in the future. This ongoing vigilance can really wear on both the person with the disease and those who love them and care for them.
Any chance of moving closer to kids and grandkids? Spending part of the year near them? Hobbies – art, music? Part time work or volunteering – anything to try and make the focus of your lives bigger.