That is difficult indeed. Citrus EOs have a lot to offer; what about other mints like spearmint?
Also I was remembering how it helps with lung health to open the chest via various kinds of exercises, putting shoulders back, head up, and sort of putting the chest out, and breathing, doing repetitions. There are hatha yoga poses that help with that and no doubt other ones. These help my lungs, as well as regulated deep breathing.
Spearmint might be ok. I know for sure peppermint and wintergreen are out.
What do you know about morniga?