Getting acclimatized to a CPAP takes work. I waited 4 months to get mine. The first night I used it - totally broken - it was assisting inhalation when I was exhaling etc. Thought I was going to have a mental breakdown. Never fell asleep. Took it back the next day and they told me it was defective and gave me a new one. Tried using a partial face. Seemed ok but big adjustment keeping my mouth shut. Then the nose piece started to occlude and choke me. Just switched to a full true face mask today. The things I do to stay alive. Meanwhile, I've totally changed my diet, given up alcohol, sugar, soda, all drinks with sugar etc, coffee, 99% of junkfood, etc. I won't turn down guacamole with chips but I can walk past all the cookies/cakes patients bring with ease. Great weight loss because of it but I think I'm stuck with the CPAP forever.