I've been on a Cpap for years and years. I literally cannot breathe lying down without it now. Before I was diagnosed with sleep apnea, I used to fall asleep while on the computer and my head would fall and hit the keyboard - I used to go to asleep on the john and wake up as I was falling off - was tired all the time. The Cpap has been a life saver literally. When I went for the sleep test, the nurses told me that they had never seen anyone stop breathing as often as I did while asleep (many many times per minute.) This can be very dangerous to your heart and can also cause strokes.
It is a little strange getting used to the mask, but believe me the alternative of not wearing it is not a good choice. I consider it a life saver and would never think of not using it now - putting it on is just as natural as breathing now.