The swallowing will cause your ears to clog, and for me I just don't swallow. If you're in the habit of doing that or are making excess saliva during the night that needs to be swallowed that can be a problem. If it's just a habit you have then you'll have to do your best to break the habit. If it's a saliva issue you need to speak with your doctor to see if there's something you can do to slow it down.
As for the asthma I've heard doctors say that asthmatics need dry air, while others have said they need moist air. Are you using a humidifier with your CPAP? If so you might try a night or two without it to see if that helps. If you're not using one you might try one out, assuming your CPAP came with a humidifier. Is your asthma not well controlled? My grandson has it pretty bad and will cough all night long if it's not controlled, but it's been very well under control lately and he sleeps without a single cough.

Hugs, what kind of mask do you use?

TMJ or tooth grinding is very common, a splint from dentist keeps teeth apart, also may stop sore mouth muscles
a football mouthguard allows teeth to grind without teeth being damaged
asthma is now sometimes treated with CPAPs

Interestingly, your TMJ itself may be causing the sleep apnea. People with TMJ usually have their jaw recessed back farther than it should be, which restricts the nasal airway (mine is about the size of a pen-shaft). TMJ also can cause congestion (mine have been clogged for about 7 years!!!! Drives me crazy!!!!).

If you treat the TMJ, it may fix the apnea and congestion as well. Its hard as hell to treat though. I've been through two orthotics, one through a neuromuscular dentist, have done acupuncture, physical therapy, you name it. Braces.. My next step is likely getting jaw surgery to move my jaw forward and open up my airway. I get extreme headaches, likely due to the grinding and lack of O2 when I'm sleeping. I'd see a TMJ specialist, though he'll probably just put you in a nightguardf, which may or may not help. You get headaches?

I get really bad headaches. I don't think that I grind my teeth because my teeth don't show it. I have tried chiropractic adjustments, but they haven't help a whole lot. I just want to be able to sleep and wake up ready for the day.

jaw clenching in sleep is related to TMJ and can cause severe aches, thru 'overclosing' of the jaw, get a splint from dentist to keep teeth apart when sleeping

most dentists know about the clenching and TMJ now