Caffeine and Sleep Apnea masks

A couple of years ago my PDoc determined that I might have sleep apnea; I did a couple of overnight sleep studies in a lab, and sure enough I do. Since then I have tried and tried to use my c-pap machine and mask but with little success. I am on my 4th mask now, having had major problems with leakage around the eyes; this is what usually stops me either falling asleep or what wakes me up a few hours later. A second problem I have is that in order to feel sleepy enough to fall asleep with the mask on my face I need to be virtually nodding off in my armchair at night before bed, ie: be REALLY tired. The catch is that due to the previous night's sleep apnea compromising the quality of sleep I've had (I stop breathing dozens of times throughout the night and snore a lot) I need caffeine to prop me up during the day or I just can't function. I try to be diligent and limit my caffeine but it is rare for me to stop at just one or two cups of coffee a day; it is more like 8 or 9. A month ago I cut out Pepsi Max entirely as I found it was buzzing me to the extent that I was awake till 3am . I also smoke 50 cigs a day. I realise I need to get my c-pap machine working desperately to be in better shape but feel like I'm in a catch-22 with the whole propping-myself-up-with caffeine bizzo. Any suggestions?