Is my DIP getting worse?

[Bri77]

I was dx with desquamative interstitial pneumonitis in Aug/07 via open lung biopsy.  I am a 30 yr old male, prior smoker for 12 yrs.  My symptoms before my intial doctor visit were shortness of breath for the past 12 months, getting worse, small productive cough, body sorness after sleep.  I had a x-ray and CT from my GP in July/07 and he refered me to a pulmonary specialist in the Houston medical center.  From there I had a pulmanry function test with a score of 47% lung function and a difffuse capacity in the low 60's, also clubbing of the fingers. Then open lung biopsy which yeilded the dx of DIP, a week after the lung biopsy I had a partial lung collaps and was readmitted to the hospitial with a chest tube for  5 days.  Since the diagnosis I was put on predisone 60 mg a day, then 40, then 30 throughout the next 4 months. In Nov/07 I had another function test that yeiled a lung function at 64% and diffuse capacity around the upper 60's, so I thought everything was going in the right direction.  In Jan/08 I had another CT scan and pulmonary function test.  The CT scan was no change from Aug/08 still a lot of fine glass and very mild/min fibrosis, the function test showed lung function at 56% and diffuse capacity at 72% but now my pulse oxygen level during mild exhurtion (showering, playing with my son) goes into the 80's and during excerise in the 70's, which now requires me to were oxygen when I exhurt myself (now when I walk for more than 3 min) and sleep.  I also feel discomfort when breathing deep breaths, like when you breath in very cold air.  My Dr who is highly recommeded seems a little dumb founded, he states I will get better in time.  My question, can dip get worse (chronic) and cause death? Can this be a DIP reaction in a form of IPF (UIP) that is slowly progressing.  What is the average time for a person with DIP to show signs of improvent?  I have asked my Dr all these questions and he states "you have a biopsy proven dip, this will cure itself with time and staying away from smoke and a lifestyle change".  I just feel things are going in the wrong direction.  Sorry for the long explanation.