As a chronic asthmatic , how do i differentiate between an acute exacerbation of my asthma and covid-19 ?

At risk: Asthma is a co-morbid condition that puts you at more risk w/ COVID, but usually, COVID symptoms include fever and a dry cough. Sometimes, the first indication is a drop in oxygen, so it might be worth your while to get an inexpensive pulse oximeter. They have them as low as $29 on Amazon. With your asthma, it's a good thing to have. It should be 95% or higher.

Do you have : worsening of your usual respiratory symptoms? Do you have other symptoms not usually seen with asthma: fever, headache, sore throat, feeling tired, loss of sense of taste/smell, decreased appetite, nausea, diarrhea, vomiting, chills without or without shaking & muscle aches. Call your doctor if more symptomatic than usual. Testing can help to differentiate.