Sleep disrupted after 5 hours with CPAP

After using a CPAP machine for about 5 years with relative success, I had a septoplasty to correct a
deviated septum. My breathing improved significantly while awake, but I have more difficulty sleeping
for more than 5 hours at a time. I seemed to need my pressure adjusted down from 10. My doctor
changed my pressure level to 8, but I continue to have problems filling up with air. If I try setting it lower than 8, I feel I am not getting enough air (as if I will suffocate). I have attempted to sleep without my
CPAP machine, but continue to stop breathing. I definitely need the machine. Any suggestions?

It might help you get more targeted replies if you register with the forum and list your equipment. In general, if your machine is not data capable, you could ask the doctor to order a trial period with a data capable autopap to help determine your current pressure need without guessing. Otherwise you're probably looking at another sleep study.