How do you communicate respectfully to someone you don't want to hear about their problems.

I have always tried to be there for people and listen when they need an ear, but this person is taking advantage and being insensitive to me. He only talks to me when he wants a shoulder to cry on. And he is so dramatic. I mean, I think he's having health problems, but he says things like he needs emergency surgery. When I ask him is he at the hospital, he is like, no they scheduled it for next week and sent me home! I am so stressed out these days with real problems, like the death of my father, sick cat, and problems with money, I really don't feel like extended myself to help someone, who quite frankly acts as if he has the monopoly on suffering. I really need him to go bug someone else right now.