I waited way too long to do mine and learned so much afterwards.
In my case, while I don't have apnea (many MANY people do, and not just fat people!), I learned that I have a deviated septum that causes airflow problems primarily during sleep, especially in our dusty ass house. (I have since installed air purifiers.)
My daily sleep quality improved considerably after using breathe right strips, Flonase and melatonin, all at the direction of my ENT. I still have episodes of maintenance insomnia (waking up at night), but they've gone way down.
I also didn't know that taking melatonin 1.5-3hr before bed and Flonase 30m before falling asleep can greatly help induce sleep quickly. Melatonin is also non-habit-forming and is produced naturally by the body, so taking SMALL amounts of it daily is completely fine. (small = 1.5-3mg)
There's other stuff that can affect sleep quality for sure (staying in bed when you can't fall back asleep; inconsistent sleep/wake times; doing things other than sleeping or aggressive snuggling), but getting a sleep study done and ruling out physical reasons is so, so, so important.
GET A SLEEP STUDY DONE!
(Also, if you're struggling with insomnia, look into CBT-I. It's hard work, but your sleep will improve demonstrably if you stick to the program. But not before getting your sleep study done!)