What Causes Tightness In The Throat With A History Of Gastric Attack?

Hi...Can anyone help me. Several months ago I was diagnosed with an acute gastritis attack. That was treated and was a one off attack. For the past two days, my throat feels very tight and is uncomfortable to wear a shirt and tie. At the moment if I apply slkight pressure to my kneck it makes me gag. I am also hiccupping and belching often. I have taken x 2 gaviscon ant acid tabs but have had no relief from the pressure and stciking feeling in my throat.