Give him the scotch. It's coming right out again as soon as the machine starts running.
Dialysis can be traumatic. Trauma amplifies mental health issues, small fears become paralyzing phobias, feeling blue becomes major clinical depression.
I would talk to him about both of you seeing a counselor or psychologist. That's a hard conversation to have, but it is really valuable in dealing with these issues.
I also knew a woman who went to a hypnotherapist to get over her fear of sticking herself. It worked.