Hi, Bill. I agree with the others that it's too early to tell. Personally, I have not seen a great deal of improvement in 3+ years of cpap. I can tell you this though, you have to become proactive in your own treatment - the sooner the better. Start by reading all the articles at the bottom of Janknitz's post. There is a wealth of information there.
I don't know anything about your machine, but you must be able to get your data daily (AHI, AI, HI, leak, pressure, hours used, etc). You don't need to be able to download it as long as you can read it and keep a log. Add to the log other variables, how did feel when when you got up ( I use a simple code: 1, 2, 3), other variables like when did you go to bed, how many times did you get up, medicine you took or didn't, caffiene after noon or anything else you feel is important. Consider making a video of yourself sleeping so you can see if you're back sleeping, thrashing, or anything that might disturb your sleep. You need to use time lapse - many of the built-in and add-on webcams come with a time lapse program. PM me if you need to download a program from the web or google Flix by Nimisis.
The main thing is to get your apnea under control, as demonstrated by the numbers and how you feel. You may have to adjust your pressure for optimal results, incrementally, with plenty of time to "settle in" after each change. Don't be surprised if your best pressure setting is quite a bit different then the one determined in your sleep study. After you feel you have obtained your best pressure settings (this could take 6 months or longer), If you are still bothered by fatigue, start looking for secondary causes. If you have your apnea under control, there are meds like Provigil or Cymbalta which can help.
Don't be afraid to look for another Doctor if you feel yours is not helping. I would guess yours is a pulmonologist, most sleep doctors are. The trouble with pulmonologist is that once your apnea is controlled, and you're not feeling better, they have no place to go. Consider getting a sleep qualified neurologist on your team as well, and find a DME that doesn't think it's a crime for you to take an active part in your treatment (it's not).
I hope this doesn't sound too negative, it's not meant to be. I just can not stress enough how important it is to get involved and educated early in your treatment. Your sleep doctor is likely to say, "try this and come back in 6 months". If the "this" didn't help, then it's 6 months wasted if your not proactive.
I'll end this on a positive note. Even though I don't feel a great deal better then when I started, my apnea is controlled and my blood pressure has dropped about 20 points. Now, that's a good thing!
Good luck, Jay