What is the reason for frequent yawning, drowsiness, and crying when reciting the Quran and praying, as well as a irritability and boredom with everything?

Yawning is from Satan. If one of you yawns, he should suppress it as much as he can, because Satan laughs if he says "ha." Therefore, one should frequently seek refuge in Allah from the accursed Satan, especially during prayer and recitation of the Qur’an, because he strives to distract the worshiper. The Prophet, peace and blessings be upon him, guided those who are afflicted by Satan's whispers during their prayer to seek refuge in Allah from him and to spit lightly to their left three times. One may also consult a psychiatrist or a ruqya practitioner.