Can food intolerances make it difficult to swallow and cause build up of mucus in throat? also can this cause anxiety?

Food intolerances : Food intolerances can elicit hyper secretion as well as swelling in the tissues which will make any mucous more noticeable. Reflux also commonly causes an over production of clear mucous a full stomach is more likely to cause problems. Anytime it feels "hard to breath", anyone! will feel a certain level of anxiety. If prone to it, yes, this will likely exacerbate things even more.