If you want to claim disability for your obstructive sleep apnea, it’s really hard, but if you can show central apnea are related to an event while on active duty, you stand a better chance. I suggest you hire a disability attorney to help you navigate the system.
That said, even if you suffer from mild or moderate unrelated obstructive sleep apnea, the new BongoRx is fully covered by the VA and the BongoRX company can ship it right to you. You need a prescription to get a real EPAP like BongoRx, but at least there’s no out of pocket costs. Get one of those rings to monitor your oxygen saturation while you sleep if you can afford the 39 bucks plus shipping. You can get them online.