breathing

Hi - thanks for your post and question - it's a good one! Although we cannot provide medical advice or diagnostics over the internet (for your own safety), your concern certainly warrants a reply.
Generally speaking, the accumulation of mucus is a well-known characteristic of COPD, which affects some, but certainly not all, patients. Having said that, depending on the amount and tenacity of one's mucus, it may have an effect on one's breathing. This may be so until the mucus can be cleared/coughed up and out.
However, the successful use of CPAP therapy hinges on a correctly sized and fitted patient interface device (the nasal prongs, mask, or cushion). In addition, the CPAP machine must be set up precisely right for every individual patient. These aspects of therapy (nasal prongs plus machine settings), are typically physician-driven and then applied by the clinician (respiratory therapist).
Since you've expressed a concern about your degree of breathing difficulty, I would suggest you reach out to both your prescribing physician and the company who provides with you the CPAP machine.
What do you think?
Leon L (author / site moderator)