Marcus,
Like Adam said, all medical questions should be directed to an AME, however, I will give you my experience. I have sleep apnea and use a CPAP machine. I knew this could cause delays for my first class so I contacted my AME and found out what they, and the FAA, would need prior to my exam. I’ll attach the information provided to AMEs on how to deal with Sleep Apnea at the end of this post. In preparation for my first class medical exam, I got a copy of my most recent sleep study and my usage history from the App that my CPAP machine uses. With regard to usage, the FAA wants to see that you actually use the prescribed machine at least 75% of the time and an average use (hours wise) of at least 6 hours per night. Knowing this, I use the machine every night, and always try to get at least 6 hours of sleep.
When I went for my exam, I printed the usage chart out, brought a printed copy of my sleep study and provided it all to my AME. They had me fill out an Airman’s Compliance Statement, basically you saying you’re using the machine as prescribed and will continue to use it until a Doctor says you no longer need to use it. And the last thing was a form that had to be filled out by my sleep doctor - basically it was asking for information taken from the sleep study and follow-up appointments to see how sleep therapy was progressing, was I using it as prescribed, what did the patient report as far as the treatment helping or not, etc. I was issued my First Class on the spot and sent the form to my doctor who filled it out and returned to me a week or two later. Once I got it, I sent it to the AME to be attached to my file and sent to the FAA.
It is possible to be issued a First Class certificate with Sleep Apnea, it is just a special issuance. I’d talk to an AME near you to get all the details and try and get your medical sorted. Any sort of delays from referral should be addressed so you can get them taken care of. If you’re going to have more hoops to jump through, might as well start jumping sooner rather than later.
Hope that helps!
Here is the link to the Sleep Apnea info provided to AMEs that should provide you with more insight.
Good luck!
-Steve