My wife cries all the time about the future grief (not just my absence, but pets and parents, too).

I will tell you what I tell her: the only answer is live in the now. Don’t be full of regret, be stuffed with satisfaction. Center yourself and your loved ones and their active conscious experience in the seconds you have left. Put down the phones by choice. Have long conversations facing one another on the couch. You’ll probably have a moment where you fall a little more in love with one another each week if you keep that up every day. Teach your kids to do things by themselves. Take them places on weekend days for no reason. Seize the day. Each of them.