Thanks for posting this question in HCM
First of all let me tell you that a given medical problem can be due to various causes and the main aim of the treating doctor is to find out the cause and deal it accordingly rather than simple assumption.
Back to your question, you are 69 and you have narcolepsy
and sleep apnea. I want to stress that in old age, one can also have coexistent sleep apnea which may not be related to narcolepsy at all. So my sincere advise to you will be to get back to your sleep medicine
consultant and get a repeat polysomnography
which will tell us if you have obstructive sleep apnea
in addition to narcolepsy. If it is so, you will certainly benefit with CPAP machine . Once aging, i advise you to repeat the PSG study. The other options for narcolepsy are modafinil