f-35 is Lightning II
have him try serratiapeptidase about $23/month, helps with cleaning out the arteries.
take him fresh food that you make, old people often don't eat much and often canned good loaded with sodium.
40 clove garlic soup is good for just about everyone, simple to make, yummy.
if he offers to give you money, take it and use it for more fresh food.
My Irish grandmother always told me to never turn down someone who wants to give you something. It's often the only hold on dignity they have left.
You are very kind to care & offer him compassion.