Does Allah choose for death a person who is very committed to worship, and is commitment to prayer, zakat, fasting, doing good deeds, and abstaining from sins sufficient for the supplication of asking for death to be answered?

Take it easy, for the matter is simpler than you expect, and no one is free from the troubles of this world. So, face them with contentment, submission, and turning to Allah. Do not wish for death, for wishing for death is disliked. Rather, say: "O Allah, grant me life if life is better for me, and cause me to die if death is better for me." Death is not related to commitment or lack thereof. Worship Allah, hoping for acceptance, and try to solve your problems through possible means. If you are experiencing a psychological crisis, consult a trustworthy doctor, for seeking treatment is a Sunnah.