i also have asthma, i dont use my inhaler as much as i used to but hopefully this info will be of some use to you
lots of guides for SN will tell you to use a beta blocker, and the most popular choice is propranolol, but some people who also have asthma have advised against using propranolol because it blocks both beta receptors, the one to your lungs and the one to your heart.
Now we want to block the receptors to the heart, but for someone who already struggles with breathing, like us with asthma, then we only need to block the heart receptor, and thats where Atenolol comes in. Atenolol is also a beta blocker but it only blocks the receptor to the heart, not the lungs, which is perfect for what we need.
I'm not 100% how peaceful going out this way will be but I've done my research on it, though as anxious about it as i am, i think i'll do more until i'm sure, hope this helps !