Well, it wasn't the CPAP machine after all.
After a concerned friend sent me a message telling me to go to the doctor (apparently, chest pressure can be a bad sign heart-wise) I decided to take his advice and visit the local doc-in-the-box. My breathing had gotten worse and my chest had started to hurt, so I hoped I wouldn't pass out in the waiting room or anything. Luckily, I was taken back surprisingly fast.
After a Stone Cold Steve Austin lookalike nurse took my vitals, I was poked, prodded, bled and x-rayed. Lots of fun, that. They ran some lab work and voila! I was diagnosed.
Turns out I have walking pneumonia. Nice, eh? That is why I can't breathe. It's not as bad as when Steve had pneumonia, but still...gross.
I was really not expecting to them find anything, so when the doctor came in and told me I said "SAY WHAT?!" She probably thought I was reacting strangely, but the only thing further from my mind was her telling me I had monkey-pox or something.
Now I have 4 lovely prescriptions to take, and I can't be around people when not necessary. I also need to be very careful who I spit on, because I can spread my filthy, filthy germs that way.
I am very, very grateful to have friends who care enough about me to scare the crap out of me, because otherwise I might have gotten much sicker and made a lot of other people sick too. :)