Hello my turtle's friend friend !
Believe it or not, precisly last night, same thing happened to me !!!!
Well, something very similar....
Well, I was sleeping and suddenly, started to "hear something", as I was very tired and sleepy, I thought I was dreaming and actually started to dream that I was in a concert listening to somebody with a very irritating voice singing very near my ears.... suddenly, I realized that noise wasnt in my dreams, but in reality and that it was coming from my lungs !
I woke up and realized I couldnt breathe and that I had a terrible cough.... It didnt stop and I looked in my mirror and I swear I was already purple/blue of my face...
(mom say I wasnt).
Anyway, it took me 1 hour and a half to realize my lungs were full of spells/mucosa but I couldnt expel it !!!!
So, fianlly I did.... but, like you, I was such in a panic attack... I couldnt breathe but I inmediately thought something was wrong with my heart and that that was causing problems with my lungs....
I thought I was going to die last night at 4:40 am.....
I was really scared.....
Sorry to hear you had a panic attack too !!!
At least it was that....
Hope you are feeling better today. I feel exhausted.