Perhaps you may have a bad case of bronchitis which has those symptoms, lots of mucus and need to cough up it up with a rattling choking sounds. Probably have post nasal drip which drains into your throat when you sleep and collects in lungs and has a bad odor. You should see a specialist in pulmonary medicine, a pulmonologist who is better than an allergist since they will look into your throat and lungs and also take mucus specimen to check for infection and bacteria. Do it right away to avoid embarassing yourself at work. They may think you have TB or some other infectious disease which may ruin your relations with them. Good luck. p.s. Green colored mucus usually is worse than yellow so pay attention and get medical help.