Late last night I posted a lengthy reply and got a message that the site was undergoing upgrades, and I see my post was did not survive that transition. Some of what I said I see is in the prior post, so I'll spare you a wordy repeat of those points.
Since you asked, here's how I see it:
1) Find out if your treatment is adequate. a) You could talk to your doctor about ordering an overnight recording oximetry study for a maybe even a few nights, but at least one, to check your oxygen levels with your current treatment. b) Confirm your current pressure needs by either having a data capable machine, getting your doctor to order a 2 week trial on an autopap, or a repeat sleep study.
2) Goggle sleep hygiene and implement the principles. Getting earlier regular sleep just may help you enough that you'll have the energy to break out of the usual boring daily routine.
3) Stand beside your bed to put your mask on to prevent falling asleep without it. I had to do that for months because sitting down was too risky. Are you using a full face mask? If not, consider if you could be opening your mouth during sleep and losing your therapy out of your mouth.
Let us know how you fare.
I've had sever apnea since 1999 and at the time I weighed 264 pounds. I'm now down to 177 pounds and guess what? I still have severe apnea. Until you go in for another sleep study you have no idea if you do or don't have apnea unless you can talk someone into watching you sleep all night. But that's a "broadside-barn" technique certainly not a sleep study analysis.
How long have you used the CPAP mask? I recall it took me more than a month to fully adjust but I wore it all night long every night. Now I love sleeping with the cpap and I can sleep 12 hours with it on if I need to. 8 hours is cake.
How long have you been using CPAP? Have you talked with your prescribing doctor about it. Your pressures and titration might need adjusted. There is just so much involved in this. You really need to involve your doctor.