You have analysed your problem quite well. I`m of the opinion that pneumonia
needs to be ruled out. You should get a complete blood count
, a xray chest, sputum examination and gram stain on it, urine re/me and a blood sugar test done. Get youself admitted in a hospital because you may need injectable antibiotics 2 to 3 times in a day for early recovery. There can be many causes of green pus. Long standing pus at any site may turn green or certain bacteria like pseudomonas
may produce green pus. Hence my suggestion is that you see a pulmonologist asap.