Too many treatments

My grandfather has sleep apnea. He has tried all the sleep apnea treatments that he was told to. The fact is that he still has problems at night. He snores very loud and sometimes he can’t breath. There are many nights when he refuses to sleep because he is afraid of death. He always says that he will die in his sleep. I am trying to convince him to go again to the clinic but he refuses everything we propose to him.