Making a Deal with myself

I am making a deal with myself to only work my coworkers awful shift once a week. I cannot do it anymore or any less. In the past 4 weekends I have had to work his awful shift from 12pm-9pm (Friday I worked my shift and his 9a-9p AHHH!) at least once or twice a week. I am really not too ecstatic about his ever fading health, yet there is not anything that my sup can do or will do as far as investigating the validity of it. I believe he is indeed ill at times, but I think at least half of it is just b.s. Working with this guy for over a year and analyzing his sickness on Mondays and Fridays there is a consistent pattern. So I think I have been stalling for some time on calling the concerns helpline when 7-8hits I will call it and voice my concerns. I don’t know what they will find, but I think he needs to retire soon. He is simply unreliable. If that make me non empathetic, then so be it. But my life is continuously interrupted due to his fading health and you can only understand so much before you are fed up with the constant disruption in your life.