How can one increase their devotion (khushu') in prayer and maintain performing all prayers on time, especially the 'Isha and Fajr prayers, to overcome the feeling of falling short towards Allah?

One must maintain prayer and not neglect it, because intentionally abandoning even one prayer is a grave sin that exposes one to Allah’s punishment. One must strive to achieve devotion (khushu') in prayer, for it is its essence and spirit. This is achieved by reflecting on the verses and invocations, by being mindful of Allah's greatness, by removing anything that distracts one from prayer, and by seeking Allah's help.