ObesityHelp

I'm so frustrated with my cpap machine!!!! It is not keeping me sleep. I wake up, on average 3-4 times a night with a very dry mouth and also with phlegm in my throat. I still wake up tired and still napping during the day. I just don't understand why I can only sleep for 2 hours on this thing and then I'm popping up. Btw, I'm on the ResMed S9 (with humifier****ep the humidifier between 65 and 70. I have been on this machine for months, I'm not a newbie. On top of all this, I take Ambien. I know for sure I should be getting at least a full 8 hours of sleep. Help me please!! I am so tired, I just want to rest. My 18 month old son is very active and keeps me busy all day long. I need my rest. My current sleep physician and I have discussed this and she keeps switching different masks but clearly that is not working. I need a solution. Should I be seeing another sleep dr or what, I don't know. Help me.