Lungs hurt when i breathe and trouble breathing?

Okay this might be kinda long...but, for the past 2 years I have been having pain in my left lung/rib. I went to the doctors and they couldn't figure out what was wrng. So I went back cuz I was having more pain and they seen a lot of fluid around my lung. They then said I had a collapsed lung. So I was in the hospital for 3 days and while I was there I had several tests done (CAT scan, ekg, upper gi, xrays, ultrasounds and much more) I got a ton of fluid removed from my left lung with this long needle and it felt a bit better after they removed it. I seen many specialists (pulmanoligist, heart specialists and a ton others) and. They still didn't know what it was causing my pain and collapsed lung. I stayed in the hospital over 3 times and was rushed to the ER about 3 times to. That was a last year though. Now lately I've been having trouble breathing and trouble catching my breath and slight lung/rib/heart pain again it gets to the point where I start freaking out cuz I think I'm gonna die cuz Its hard to catch my breath. The only way I can catch my breath is by yawning..I was just wondering...what do you think this could be causing all this?? And what should I do??