I am 75 in poor health (one lung asthma bronchiectesis etc) with a band C. on housing list at moment in b&b emergency housing for 6 weeks how can I improve this band?

Just go hospital or clinic and make consolation with the doctor who can treat your condition in a proper way. With that, you can follow some home-based natural therapy like "salt therapy" using certain device as "saltair" which can be found through stores like "salinetherapy"