Can constant thick mucus running down my throat cause a constant BAD sore throat?

I have had a constant sore throat since I had my tonsils removed 8 years ago. It gets so bad sometimes I just cry and cry. I have tried some antihistamines but doesn't stop the pain. I have tried so much but now, 8 years later my sore throat pain is so bad that I can't really work and I don't hardley even want to get out. The pain is too much. IB Profun doesn't help anymore. I don't drink milk and don't have dairy products very often at all. Many times when I look at my throat in the mirror I see mucus draining down and it is VERY thick. I need this pain to stop because I need to work and I want to enjoy life again. Could this be the cause of the pain? Also, things that have benzocaine in them like throat drops burn my throat. Couldn't it burn because my throat is raw from drainage? Thank you so much for yout time!!