Can a heavily asthmatic 22 yr old get pertussis again after having it a year ago? signs of flu but with nausea

Possible but ....: While it is possible to get pertussis more than once, it is very unusual unless you are immunosuppressed for some reason. With a history of "heavy asthma", it is as likely you have one of many other viral respiratory germs which have caused your asthma to act up and thus the unrelenting cough. There are tests that can be done, so if highly suspicious, just have your doctor swab you and know!