Welcome to HCM.
I am suspecting the flu which starts as common cold
and can later cause cough and chest congestion. Rhinitis
also as such is more commonly caused by viruses and more during the cold season. Stress may have effect on a persons immunity to a some extent. Stress can cause release of hormones like adrenaline
which alter the immune responses in the body. Chronic stress can prove to be harmful. I suggest to cope with the stress but in a healthy way. Thanks.