Help!! Went from CPAP 15 to BIPAP 28 LEAKS AND PAINFUL

Sorry so long just wanted to make sure you have all the facts. I have been on a cpap (several different machines) a long time since 1994 (the very 1st test done at Keesler AFB in MS) and it was set at some low pressure like 8 or 10 using a nasal mask and chin strap. During this time, I was within body standards for the military and maintained the standard through the beginning of 2004 when I retired. I went for another sleep study at the VA and they set me up with a Respironics Remstar Auto System One with a pressure of 15. I have always been a mouth breather so when the pressure increased I moved to a full face along with a chin strap. Slept on this thing until I started always feeling tired again and continued this for about a year. Finally went to a Neurologist and had 2 sleep studies and they found several sever sleep problems including night terrors and such. Plus, like most folks I have gained lots of weight over the last 4-5 years after having neck, back, both shoulder rotator cuffs, knee replacement and 3 stints after a small heart attack. They have put me on a Resmed S-9 BIPAP UPAP COPD with a pressure of 28/24. I am having problems a mask that does not leak. I have tried the following: Fisher & Paykel Forma Full face small, Resmed Airfit F 20 medium Resmed Mirage Quatro small and a med. And all leak bunches and wake up and find the bottom of the mask in my mouth. Cut/bruises my nose ect…Thinking about trying a FULL FACE MASK like firefighters use. I do have a few extra masks here that I tried one or twice with my old machine but did not like. I have a F&P 431 med, Resmed Ultra Mirage med, Respironics Amara View med, and a Respcare Hybrid full face with small, med and large gels. All the masks I have tried so far I have to over tighten which hurts and always leaking and it runs the wife out to a spare bed room. Also use cheek pads and Gecko nasal pad to no avail. Anyone have any ideas or experience with this high of pressure. Any ideas for masks? Any tricks? Oh yeah saw video about using a karate mouth guard so ordered several, heated in water and formed for mouth but still did not keep my mouth shut.

My max pressure is 20. I love using nasal pillow masks as I find they seal so well. Currently using P-10 and love it. To control mouth leaking I have been using the Ultimate Chin Strap for eight years. It closes the jaw, covers the mouth to limit leaking, and keeps the cheeks from puffing out.

Wow. I feel for you. Keeping my leaks to a minimum is hard enough at 18. 28 must be a bear.

get some sleepy head charts up, 28/24 is pretty high pressure. Whatever mask you use, it can't leak.
I would also get a $10 foam cervical collar to rule out positional apnea, like chin tucking. That is my initial guess to what could be the change.