Hi, Ed.
What kind of mask are you using? There are many more to choose from than what the RT may have shown you. Some people find a nose-only mask less stifling whereas others like the air flow of a full face mask. There is also one that goes around the perimeter of the face, etc. We settled on the Circadiance nasal mask in the later ALS years, but used many others over the pre-ALS (OSA) years.
The BiPAP is a scary contraption, no doubt, but give it time and the right care & feeding, and it can be a good partner. Let me know if you want help with the settings. If you are waking up with it, you may not have the right adjustments to go into deep sleep. My husband was claustrophobic (e.g. used to get sedated before CTs/MRIs) so I have an idea of how daunting it can seem.
Best,
Laurie