In the past 3 months i've had covid twice, a chest infection, strep throat twice and the odd cold, i'm scared i've got cancer or something. now i just can't stop coughing constantly?

You probably have post inflammatory lung syndrome because of repeated respiratory infection. Persistent cough may be present in this syndrome. You should see a lung doctor (pulmonologist) for a thorough assessment and treatment.

Pulmonary function testing and a chest image are usually indicated. Bronchospasm should be ruled out. Another infection may have occurred and a complete blood count and differential is recommended. Watch for signs of shortness of breath, chest pain and wheezing.