Can someone help me with this?

When I lived in the south a few years back, I used to cough up alot of phlegm, and when it would get cold out I would lose my voice for about a week, I suspect due to mucuous buildup. Now, I'm more northern and never lose my voice but I'm noticing some phlegm buildup in the back of my throat that is hard to get rid of. I also experience a very bad taste in the back of the throat area like something is infected. It also smells really bad despite tons of mouthwash and mint chewing gum. Can someone help? Tweet