CPAP Issues experienced by long-term user

I am 63 years old and have used a CPAP machine for approximately 20 years and suddenly experiencing difficulty with my RESMED Airsense 10 Machine and nasal mask that are limiting my sleep to two hours at a clip only. I use a RESMED Airlift N20 and have been experiencing severe difficulty getting the nose piece to get a proper seal. I had suspected that this was an issue with the quality of the plastic they use which after just a few uses becomes overly soft and collapses during use requiring me to over tighten and loosen the mask over and over to get the correct fit. Additionally, the EPR setting on my machine was normally set to 3 does not seem to be getting me to that comfortable breathing rhythm that I have been accustomed to achieving previously. last night I change the EPR from 3 to 2 which allowed me to get some sleep but not sure the problem is resolved. Has anyone experienced issues with the Airsens 10 EPR or pressure settings or with substandard nose pieces that may be contributing to my current issues? I am extremely fatigued and nNeed to fix this quickly so I can get a full night sleep.