Hello there, Old Married Man. That is really tough, watching both parents decline. And having lost your youngest son to cancer, the anticipatory grief does stir up the grief of losing your son, and pretty much any other loss you've ever experienced. That's the way grief is: it combines with other losses and sometimes you can grief them all at once and heal a bit more. Other times it just seems overwhelmingly sad. And on those days you practice self care: something healthy for your body, like taking a walk, something healthy for your spirit, which can be listening to your favorite record from long ago or going to a church service (I go to church for the music, the people, and the sermon, in that order.) Self care for your social self can mean calling up an old friend, or calling up your other child(ren) to catch up on what they're doing. Watch some 'america's funniest home videos' on youtube. Or just take a very long nap in the middle of the day.
Hospice team folks can tell you about dentures and hearing aides. My guess is that there is a 'work around' for not having the right or enough or any dentures. If they are slowly declining, they are not eating a lot. Hearing aids are expensive: if he has some old ones, perhaps a visit to the audiologist to adjust those aids might do the trick. But ask the hospice social worker or nurse. Or the nursing home social worker or nurse.
Is there anything you can do while you visit your folks that would make them and you feel better? Bring in some music on your phone and play their favorite tunes. Or bring in a photo album. Or bring in some baby oil and give each hand a gentle massage. I know its hard. I used to visit my father in the nursing home he lived in for 7 years very regularly. It always felt heavy. When he did start declining and hospice joined the team, my sister and i took turns living in the chair next to his bed, with his wife visiting during the day. He was comfortable. And it was very sad.
I hope your wife and other children and maybe grandchildren give you some pleasure. And I hope the hospice group has a bereavement group for afterwards. Thanks for writing. Write more if you want to.
Jane