Hi Pat I don’t have any insight or knowledge into sleep apnea, I do have experience of my partner being possessed when asleep mostly after alcohol. He will scream kick, punch out whilst asleep and act like he is having a conversation with someone. One occassion the neighbours called the police because he constantly shouted help, He was referred to the sleep clinic and was sent home wired up to a monitor
maybe they will start with sending you home wired up rather than send you to a sleep clinic.
Sorry to hear your health isn’t good sending magic healing dust.