What is the reason for feeling a lump in the throat and a lack of inner peace when reciting supplications (du'a), especially from a paper, and does this affect their acceptance, and are there special manners for reciting supplications from a paper?

Supplication has a great effect on the tranquility of the heart, and it is an act of worship. Allah Almighty says: "And when My servants ask you concerning Me, then indeed I am near. I respond to the invocation of the supplicant when he invokes Me." One can increase in recited or written supplications, and there is no difference between them. Do not read a long supplication if it causes you boredom or a feeling of shortcoming; rather, a short supplication that brings tranquility is sufficient. The feeling of shortcoming or lack of response may be from Satan, so seek refuge in Allah and increase your supplications while being mindful of the conditions for their acceptance and their etiquettes.