I'm sorry for your stress. I know this cycle well; stress with from friends being irritated with me, leads to anxiety, leads to asthma, which causes more anxiety and asthma. (Of course, for me, in pollen season, asthma comes from a different cause.)
I agree, treating the asthma, first and foremost, is the most important thing., so you can relax, rest, and think clearly. I'd encourage you to spend time, at this time, with anyone who enjoys you and who is not irritated with you.
After years of trying to tolerate and please friends and lovers who were, by nature, irritable, I finally saw that I was not too sensitive, nor had I done anything wrong. Slowly, I transitioned friends, and the panic attacks and asthma have almost disappeared. Now, my new closest friends are respectful, don't constantly through irritation and anger my way, in attempts to control me.
This change occurred from me realizing how I was so pre-occupied with their comments, that I couldn't sleep. When attempted to problem solve with them, they insisted they were right. (Also,I saw how I was choosing lose friends who were like my parents.) Since my friends weren't interested in changing, I saw that the only way for my physical and emotional health to get better, was for me to make new friends, who don't threaten me, directly, or indirectly.
Your situation is unique to you. I hope my story can support you to know, that you are not at fault, that you are a good person, your friends have anger issues, and that things can get better, if you make new choices, in your own way. Good wishes to you!