CPAP Settings Upped

My CPAP settings pre-op was 14, then 6 months after surgery it was lowered to 8.  I had got a little non-compliant for a little while, and then started to wear it again earlier this year but had trouble, so didn't wear it for a few months, then in spring I tried it again, and it just felt like I was gagging for air, like a pillow on my face.  So a few months later I try again and same thing.  So I finally get in for another sleep study and they put my settings back up to 14.   I don't know why my settings needed to be raised so high.  
I already knew that my Sleep Apnea was not related to my obesity as I had it all my life, since I was a baby.  But I did know that the obesity made it worse. 

Also on the same note, my first 2 nights wearing my CPAP on 14, I awoke numerous times with the need to burp and having to literally burp myself.  When I woke up in the morning, it felt like someone air-dried my entire insides.  I swallowed air throughout the night, I never had so much "gas" inside of me and my CPAP nurse told me to try and walk it out.  Why would the air be going down to my stomach instead of my lungs?  What kind of damage can this do to my pouch?  I don't want it to get stretched out or irritated.  

I don't go back to the CPAP doctor at the hospital until Dec 7th. 

Are you using the mask?  If so, maybe you would do better with the nose piece instead.