I Have Been On Prednisone 50 Mg For Five Weeks.

I have been on Prednisone 50 mg for five weeks. The first four were because of pneumonia, but that has cleared, but my asthma continues to be out of control. I have gained 20 lbs and am puffy all over. I am on other meds, Advair and Singulair to control it, but the pneumonia set it off. What can I do? I can't breath and I keep gaining weight, which also impedes breathing. Any suggestions would be welcome. Thanks, Renatta