Hello, I've Had A Terrible And Constant Cough For About

Hello, I've had a terrible and constant cough for about a week now. I've been coughing up flem, and today it started tasting like latex. Why is that? When I cough, it leaves a nasty taste in my mouth. It's like a "wet cough" and once I start I can't stop. I can't bend down/over without coughing up my lungs. Ive had stomach aches, my appetite is gone, and ive had a fever. What should I do?