What Could Cause Chronic Severe Throat Pain After Inhaling Dust?

I had accidentally inhaled a dust through my mouth. I coughed a lot yet I was able to feel that dust at particular place. Since then I have severe pain in my right side of throat. Believe me I felt I was able to move the dust when I inserted my finger into my throat . And the symptoms would change accordingly.. I cannot keep my throat at a particular position or else it pains, swallowing saliva also pains. This all is happening since 8 months. I have been prescriped duselpin 50 mg the pain is decreasing but increases if I talk too much or the I swallow after a pause and I feel like coughing all time. It s not like any normal pain and the pain is very very excruciating and I hate it. I take montair fx and ibuprofen daily morning. To tackle pain but the pain never goes. It s really painful. Dr did an endoscopy and said there s no inflammation to suggest foreign body presence. I even did an mri for my satisfaction. The pain is literally killing me. . Steam inhalation and montair fx seems to help only partially.. The pain seems to be more of musculoskeletal in origin. Pls help me to tackle pain