Wondering if High Pressure is causing other problems

I've been using my CPAP since 2005 and my pressure is 11 and I noticed at night that it does leak and I have to wear a chin strap in order to keep the air from coming out of my mouth however it works for me but sometimes I have to get up in the middle of the night and drink lots of water because my throat and esophagus is very dry now I also have numbness in my feet in the center of my feet and I'm not sure if the dryness is causing other side effects if anybody else is having this please let me know I am lowering the pressure on my CPAP today and hoping that I don't have air leaking out of my mouth any suggestions would be greatly appreciated

I use a nasal mask with chin strap and sometimes get dry mouth. Have not had any numbness in my feet. I would doubt that CPAP therapy is causing that. Do you have a humidifier with your CPAP machine? I have to set my humidifier to near maximum temperature (heated hose) to keep from getting dry mouth and even then, sometimes it still occurs. If you don't have a humidifier, I would invest in one. I also have an oral appliance and get dry mouth every night, because of a lack of humidifier. My pressure is set at 5 - 15.