I also have severe asthma and never smoked. I am sorry to hear that you also have COPD and have to use oxygen.
I take an injection of Xolair monthly which does keep me out of the hospital. It is only for severe asthmatics and costs around $10,000 per year. My insurance pays most of it. You might ask your doctor about it. More insurance companies are paying for it these days because it saves them money by keeping patients out of the hospitals and the ER's.
Good luck to you!