Breathing problems and how long can this last?

Hello,

I am a very healthy 41 year old women who has never had any health issues until last xmas. I'm trying to recover from pericarditis as I had a pericardial window surgery on new year's eve 2009 and two months later it is still lingering. I was tested for what feels like everything under the sun and the good news is that everything came up negative (lups, TB, etc). The only symptoms i seem to have left are shortness of breath, which greatly affects my sleeping (even now being on indomethacin and colchicine for awhile). And, I'm tired but i'm not sure if this is from the meds or pericarditis.

My question is, can pericarditis really last 3+ months or longer without it turning into Constrictive pericarditis? My last echo and angioCT shows some thickening of the pericardiam and I have some good doctors monitoring this with me so I'm trying to be patient and just hope that with more rest this shortness of breath, which comes and goes, will eventually go away? I'm really afraid of getting constrictive pericarditis but as i keep having these bouts of shortness of breath it makes me feel like it is going in this direction. Could the thickness of my pericardium still be because of the inflammation?