Hi thanks for contacting HCM. Noted you have main complaint is of cough. Let me know you whether it is dry or wet cough???? You might had viral flu infection .... So it can lead cough as by infecting respiratory tract.... Let me know you if you have acid reflux disease then also by irritation cough can occur. Do you smoking? As here bronchitis like condition might lead cough .chest x ray useful which show prominent bronchovascular marking... Metallic taste here I think need not much concern.Maintain oral hygiene for it. Drink more water... Avoid respiratory irritant like pollution smoke, cigarette smoke, spicy food etc.... I hope your concern solved. Dr.Parth