I was hospitalised a couple of weeks ago with a severe attack taking me down to 150. They let me out with 5 days of prensidone.
My peak flow is now an amazing 650, most mornings pre meds, which is better than my previous best of 622! However regular attacks take me down to 400, and any exercise like walking around a shop leaves me breathless.
How long will it before things settle down.
Sorry to hear this
It might take quite a while
Me it takes a month recovery
Discuss with care team?
it takes awhile for the body to get used to coming off prednisone. I used my rescue inhaler more often for a few days.
I recommend highly Pulmonary Wellness.org
This site has free, academic info and recommendations for pulmonary disorders for the layman. It also has a FB page. No nonsense.
It helped me a lot and I am a retired nurse anesthetist with asthma and scoliotic restrictive lung disease.
Peak Flow doesn't always drop despite being symptomatic. 
Testing positive for covid 
biological not working
How long before you felt benefit? Biologics - Nucala 
