I've had this really bad cough for four days now and my doctor asked me to get a chest x-ray. The report mentioned something about patchy haziness in the lower right zone, which they said might suggest pneumonitis. I'm kinda worried because there's also blood in my sputum in the morning, though it turns to just yellow sputum later in the day. Could this be something serious? What should I be doing about it?

It sounds like you have a case of pneumonitis, which is causing inflammation in the lung tissue, and the blood in your sputum could be due to irritation or mild bleeding from the airways. The yellow sputum suggests an ongoing infection. It's important to follow up with your doctor for appropriate treatment, such as antibiotics or other therapies, to help with healing.