What is the reason for the sudden cessation of acts of worship after marriage, and how can one return to their previous state and even better?

Your discontinuation of some acts of worship may be due to a change in your lifestyle and your preoccupation with the burdens of marriage. Your good devotion to your husband and excellent companionship with him are among the greatest acts of worship through which you draw near to Allah, for the Prophet, peace and blessings be upon him, said: "If a woman prays her five [daily prayers], fasts her month [Ramadan], guards her chastity, and obeys her husband, it will be said to her: 'Enter Paradise through whichever of its gates you wish.'" Nevertheless, you should strive to increase in acts of worship you are capable of, such as prayer, fasting, and charity. What helps you with this is pondering Allah's names and attributes, and reflecting on death and its horrors, and avoiding causes of hardness of heart such as heedlessness and excessive focus on worldly matters. Increase in the remembrance of Allah and supplication, and strive against your soul to do good, for through striving and seeking Allah's help, you will return to what you were and even better. And if you fear not being able to wake up for Witr prayer, then praying it before sleeping is better, and there is no sin upon you if you miss a prayer due to an excuse like sleep. Seek out reasons for softness of heart, such as meditating on the Quran and accompanying the righteous.