Sleep Apnea After DS Surgery

I've had Severe OSA for many years, now this year I am down 75lbs, (from 497 back in Jan 2015) and I had my DS surgery back in late November, but now I don't feel well rested.  This is a sleepiness issue, not an energy issue.  Feel the same as I did before I had my Bi-pap, almost as if the bi-pap is now working against me in the sleep department.  Any one else have this?  If so, did you have to get your settings adjusted?  I've tried taking a nap without the bi-pap, and still feel like I can't fall asleep without it, but not sleeping well with it.  Its been 4 weeks post op and I'm still not feeling rested.  I have a apt for a new sleep study, but in the waiting mean time, any ideas?  Ive tried lowering my pressures, and it seems to have helped some. 

Any ideas?

I see that you wrote your post in November.  I hope you had your air pressure levels adjusted by now.  Absolutely, with a weight loss of 75 lbs, your pressure needs will change (likely drop).  If your machine doesn't monitor you each month adjust itself, please have a professional adjust it.  It likely has an SD card in it (or some memory card of some sort).  They can look at the readings for it and adjust it to what you need.  Having too little pressure will have you waking up because you're not breathing.  Having too much pressure can cause problems with the heart for example, especially if there are problems like congestive heart failure (not saying that's your case).  Best of luck.