Coughing up mucus from lungs. its yellowish green and it tastes horrible. does that mean it's bacterial or viral?

Unfortunately no: It turns out that mucous colors have limited predictive value for distinguishing between viral vs bacterial infections!

Productive cough: We used to think that colored mucus was a sure sign of a bacterial infection, but that is not always the case. Often, discolored mucus may be draining from the sinuses vs the lungs. Get an evaluation if this persists.