I'm so sorry you are having this problem! It must be terrible for you. Have you seen your doctor lately? It sounds like getting rid of the phlem helps you to be able to talk. One thing I've always used to get rid of phlem is Listerine, the original flavor not the new blue and green ones. They don't work as well as the original one. Gargle with it several times a day. That should break up the phlem quite well for you.
I wish you the best.
PML