Hello. I Am 45yrs Female. Diagnosed With Asthma In 1990.

Hello. I am 45yrs female. Diagnosed with asthma in 1990. Currently been taking Fostair (pink) inhaler twice daily. Peak flow max average between 380-400. No real problems until now. Recently 5 days ago started to have breathing difficulties. Ended up in emergency on Thursday with asthma attack, received nebuliser and Prednisolone. Home now with Prednisolone 6xtabs and Ventolin inhaler. Is it normal to feel exhaustion, still coughing. So fatigued after this. How long should recovery last after an attack please? Thankyou. Amanda