It is frustrating when the thing that you count on helping you in one realm causes issues of its own in another. You are probably going to have to do a process of elimination to sort through your problems.
My first thought is humidification - either too much or too little can cause swelling and congestion. If my air is too warm, my sinuses feel awful. Some swear by the warmer the better. You'll have to figure out what's best for you. Also, when I was trying to use a nasal mask I found it was either a bad fitting mask or else a bad fitting style for my sensitivities. The pressure on the sides of my nose/cheeks caused the sinuses to be closed and the sensation was intolerable. No medication could have opened them because external pressure was the issue.
Early on I had pains in my back, chest & upper abdomen, I think due to trapped air. I still get a bit of air that makes its way in my belly (have a hiatal hernia and GERD). I would never advise anyone to ignore chest pain. Just saying it's commonly reported on here. If you are pretty sure it is treatment related as mine was, you could experiment with positions. I find I get more trapped air if I start my night on my left side. Not sure why. You mention bronchitis and tightness - do you have a cough or wheezing or seen a doctor or are you just thinking that your combination of symptoms sounds like bronchitis? You may need medical attention if it is bronchitis.
You might find it helpful to keep a little journal as maybe a pattern will emerge that will help you optimize your treatment and minimize you side effects. I'm sure others will come along with thoughts on what you can try too. Treating OSA is in the long run worth sorting through the aggravations. Best wishes finding some solutions.
P.S. I see while I was typing others have posted. In case of duplication, just consider me a co-signer.