after i eat, i keep needing to burp, but when i do, i can feel liquid in my throat, just above my collarbone, and it's quite warm. it feels like a lump in my throat, but it's quite low down. I also get burning pains in my upper abdomen, and when i touch the area, it prickles. I went to the doctors, and i was told to take gaviscon for 2 weeks, which i have done, but i am still getting the same symptoms. Do you have any idea what this could be?