Why has the questioner's religiosity declined and her personality changed for the worse after marriage, even though she used to pray for marriage to be a means of greater commitment to Allah's religion?

The servant is responsible for the calamities that befall him because he chose the path of disobedience. He must repent and return to Allah. What befell the servant might be a trial from Allah to purify and cleanse him, or it might be a punishment for his negligence. The matter requires sincere repentance and seeking Allah’s help. Its remedy lies in relying on Allah, having a good opinion of Him, and persistently supplicating.