I didn't even know I had sleep apnea. I knew I had insomnia, but apnea had never occurred to me. The first time I saw my current neurologist, which was 3 years ago, he took one look at me and said, "The first thing we are going to do is a sleep study for apnea." My first thought was, he must be kidding, even though I have 2 sons that had recently been diagnosed with it...even though I knew it tended to run in families. I even said, "You have got to be kidding!" He then told me, he could tell by my facial features, told me to
open my mouth, then said something that made me laugh. He says, "Your mouth is too small!" I asked him to give me that in writing so I could show the rest of my family! He then told me that my breathing passages were too small..he never told me I was too heavy and the weight was more than likely putting too much pressure on the breathing passages. After being diagnosed with sleep apnea and researching it, other symptoms popped up. Like the waking in the night in fear, which is usually from the times when you stop breathing, you think it was a dream, but it's the fear of not breathing. Both of my sons were much worse than me, one son is at the point if his gets any worse he will need two machines. His pressure vamps down to where mine was set at its highest. Last summer I had a 2nd sleep study done and they lowered my pressure to 7. I had lost 60# by then, 30# more later, the machine was waking me up so I stopped using it. At that point, they did decide the pressure was off my neck and breathing passages.
I never really did change much while on the CPAP. I didn't wake up in fear, so at least I wasn't having issues with my breathing any longer on CPAP. My insomnia continued until I realized I was intolerant to dairy..one day off dairy and I slept through the night. I tested the theory several times...dairy=insomnia. There also are several different types of insomnia. I sleep fine now, but I do not rest..this seems to be a symptom of fibro.
I do think, if you ask the ENT for a sleep study, he/she will refer you to another doctor. If you do get a diagnosis and start CPAP, don't get discouraged if things do not work out the way you hope from the beginning. There is an adjustment period, often times the masks are difficult and you have to try many before you find one that works well for you. It's a science like everything else.
Good luck.