You can call me NIK
((((Guinness and family))))
Best advice I can give is to show up (whether in person or with regular phone calls) and listen. When my father's brother died, it hit him in a way that changed him. He became very aware of his mortality. For a while it manifested as depression, but it eventually turned into a drive to live for the day and enjoy each day as fully as he could. He also became semi obsessed with family history. He gathered stories and pictures to ensure his brother's life(and his own) would be recorded and remembered.
Don't know if any of this helps. Sending you strength.
“The most difficult times for many of us are the ones we give ourselves.”
― Pema Chödrön