Hi Jenn. I actually lived on BiPAP prior to being vented chronically and really felt like it helped tremendously. BiPAP has two pressures, one higher upon inspiration and one lower with exhalation somewhat simulating breathing. It actually did feel close to "normal" breathing and allowed me to rest my very tired muscles.
CPAP is one continuous pressure, it does not vary with the breathing cycle. It is great for those with sleep apnea, that continuous pressure keeps the airways from being occluded which seems to be the biggest culprit amongst those with apnea. BiPAP is used for those who have CO2 retention, or severe weakness or fatigue of the muscles (this is what happened to me). I had a terrible problem with CPAP when it came to exhaling. My muscles at the time were unable to breathe against the pressures needed to sustain me and so BiPAP was the answer.
I lived on BiPAP for a few years with O2 supplementation and then switched to the vent once it became clear that BiPAP would no longer sustain me. I think the hardest thing was getting used to the masks and or nasal pillows. My skin broke out easily and it took a few different brands and size changes before I found the right mask/nasal pillows.
I hope that you turn around soon and are out of that hospital. I am glad that BiPAP is helping though. Sending hugs and well wishes, Jenn