Hi,
Noted your history about getting diagnosed with 
pneumonia after a CTPA (suspected 
pulmonary embolism). One symptom that you are experiencing together with the painful chest when breathing, are itchy hands and balls of the feet. The most common causes I can think about are as follows:
Bacterimia or 
septicemia can cause such symptoms wherein the bacteria or the toxins produced by bacteria get settled in most distal parts.
Allergy to anything like medicines or foods with preservative.
I would advise you the following in such a situation:
Consult your Doctor who on examination can think of the most proper cause and treat you accordingly.
I am sure about you being a proper antibiotic cover, symptomatic and supportive management which you should continue till you are cured as it takes longer than the usual infections.
Painful chest on breathing indicate involvement of 
pleura that is covering of the lungs.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, General Surgeon