Most cold viruses last between 7 to 14 days before going away fully.
You're usually contagious with the cold virus for up to 4 to 5 days depending on the severity of the cold virus you have.
You'll usually experience the worst of the cold virus with symptoms such as headache, fatigue, tiredness, sore throat, runny nose, cough, discomfort, sneezing, fever, clear, watery discharge from your nose and body aches.
Those symptoms should go away within 4 to 5 days but you may still experience coughing and coughing up phlegm for a few days or so after the cold virus goes away.
Even sneezing can continue along with a runny nose for a few days after the cold virus gets out of your body.
If the cold virus hasn't gone away within 14 days then you should probably see a doctor about it.
But most times the cold virus goes away within a week to 14 days without medical treatment.
I would advise using a humidifier or vaporizer as well as taking hot showers or sitting in the bathroom with the shower on the hottest setting so that it puts out steam to help you breathe better.
Take some cold medicine and get plenty of rest and Vitamin C as well such as through drinking orange juice or eating oranges.