Sometimes it just takes some time, but sometimes you can tweak some things and make it even better.
Think of your apnea as being like smoking two packs of cigarettes a day. When you stop, it takes a while to get over the after effects.
Do you know what your AHI was during your sleep study?
By the way, you say you have ResScan, but you have a Philips Respironics machine. They don't work together.
Get the free SleepyHead software here
for information on the main alternative to CPAP.
If it's midnight and a DME tells you it's dark outside, go and check it yourself.
Sclark, I used to think all that was needed was to use the machine 100% of sleep time and eventually, say in three months, you would feel better. Then I learned that without good sleep- REM and deep sleep your body does not repair the damage of the day. Your AHI is very good- with a little time and good sleep you should note some improvement soon. When I switcted to an ASV machine I gave myself six months to a year for the machine and I to work in sync. Nine months later I was feeling great.
Another consideration is your current state of health. If you haven't had a thorough physical with bloodwork this may be a good time to rule out problems such as hypothyroid, diabetes, anemia to name a few.
Good luck, keep us posted on how you're doing.