AirSense 11 & AirFit F30i Mask, new CPAP user

[TreeSky]

Hello and thank you for keeping this resource alive for new folks!  I just started CPAP therapy on Wednesday and would like to get some of your insight and experience to help me get the most out of it. 

About Me:

• Diagnosed moderate OSA last month with an AHI of 27.9
  
• AirSense11 with AirFit F30i Mask
  
• Pressures: 5 to 15 (I like it best around 8-10)
  
• Lifelong stomach sleeper/mouth breather
  

Obviously, the mask is leaking big time.  I sleep on my stomach with my arms up under my head on the pillow.  My face is to the left or right and I alternate sides throughout the night.  I can't seem to get used to the little nose air holes since as a mouth breather, they're useless to me.  I think I was using them while sleeping the night before last because when I woke up yesterday I had a nosebleed. I have since increased the humidity and tube temperature and this morning: no nosebleed.  That could also be from not breathing through my nose at all, too!  If I use my nose to breathe, my sinuses immediately hurt even at 5.0 pressure. Even mouth breathing, I cough when the machine first goes on until my throat stops being dry and scratchy from it.

When I was waking up this morning my breathing sounded like Darth Vader, but there was no air blowing in my eyes or coming out on my cheeks, so I am not sure where it would be leaking from!  When I use the Mask Fit feature on the machine, it always tells me I have a great seal - but that's when I'm awake!  It even once told me I had a great mask seal when I wasn't even wearing the mask! Way to confuse the newbie, ResMed!

I have it set to SmartStart so that if it stops from a leak in the night, I can just restart it with one breath.  I do not recall this happening during the night, but I was asleep so how would I know!  I suspect my issue might be more positional than anything?  Maybe I have a bad mask/machine?  The mask fits snugly; not too loose or tight.  

I'm open to suggestions from experienced users as I really see the potential for improving my overall well-being, and would like to get past these issues.

Thanks for reading!