What Causes Food To Stuck In The Throat?

I am having digestion problem for over one and a half year now. its more like i the foods i eat dont digest, rather it gets stuck in my throat or keeps coming back upwards and creates a kind of acid. i dont feel like i have gas in my stomach but the food pipe area gets all acidic. at several occasions i almost couldnt breath for few secs and got scared to death. one doc said i have a disease called gerd. another doctor said another disease (name on which i couldn't get properly). some docs sid its nothing but out of stress. i have had cintapride and lansoprazol for an year. last two months my new doctor gave me multiflora and dietary suppliment, omidon and nexum. whenever i take medicine, i feel fine. but the moment i dont take medicine, i start having all the acidic reaction all over again. please help me if my descriptions make any sense to you.
ps. on my first endoscopy doc found a popypus, on second endoscopy the found three more. i did once in a year.