Welcome to Healing Well! I did have very bad breathing problems, however they were from reflux, rather than pressure. Still, I think that there are similarities in that both of us had problems for a long time, and it takes a long time to undo what was done prior to our surgeries. It took me two and a half months to begin to see improvements in my lungs...at that point, I was able to stop daily nebulizer treatments, and I knew that the reflux had been the cause of my severe issues.
I think you will find improvements as you heal. It's not an immediate change...it didn't get that way overnight, and it won't go away overnight.
Hang in there...it'll get better.
let us know how it goes!