jr, in adddition to the excellent advice that cowlypso has given you, many of the new machines have a ramp feature that the providers (DMEs) LOVE to set at 4 cm pressure. However, to most "normal" (with apologies to those who do only require that pressure!) 4 cm is too low - you feel like you are suffocating. You are trying so hard to get extra air in with each breath that you actually feel like you are struggling to breathe out. So, the first thing to do is check whether you have the ramp feature turned on. If it is on, what pressure is it set at? If it is lower than your prescribed pressure, you should be able to increase the starting pressure by 1 or 2 cm (until you get to your prescribed pressure). If you can't figure out how to do that, you need to demand that your DME shows you. The ramp pressure is a COMFORT setting that makes no difference to your treatment except to make you more comfortable at the start. If you are not comfortable with it, something is wrong!
If that doesn't work, maybe your pressure is too low. If so, you need to talk with your DME again, because they can help ease the path to the sleep doc.
Please be proactive about your treatment - you don't have to suffer in silence! Your DME and doc will let you if you want, but that is not the way to get the best treatment for YOU!
Diagnosed September 2009, Respironics System One w/ C-flex and humidifier
Aloha nasal pillows
Not a medical professional, just a patient with severe OSA (31) who has done a lot of reading.