My 3 Yo Is Having Difficulty Swallowing Solids Which Started

My 3 yo is having difficulty swallowing solids which started 7 days ago and clearing his throat which started 4 weeks ago. In between he did have a cough and congestion that resolved. About 12 days ago he had two episodes in the same day where he grabbed his chest in the middle of eating and started crying; once with apples and once with waffles. He was not choking. He had a negative chest xray and a normal barium swallow. He wants to eat. He does not seem afraid to swallow more a difficulty to swallow. Any ideas?