What is the interpretation of the negative changes that have occurred in my religious state, such as feeling distressed when reading the Qur’an and being sluggish in prayer, seeing myself falling in dreams, hearing strange voices when reciting adhkar (remembrances), along with a feeling of hypocrisy, lying, and committing sins despite sincere repentance, and is this a tribulation or a sealing of the heart?

The feeling of pain due to your distance from Allah is an indication of the vitality of your heart. You should follow this feeling with a serious attempt to change and remove yourself from your current state, for happiness is intertwined with a servant's closeness to his Lord and his diligence in obeying Him. Allah Almighty said: "Whoever does righteousness, whether male or female, while he is a believer - We will surely cause him to live a good life, and We will surely give them their reward [in the Hereafter] according to the best of what they used to do." (An-Nahl: 97) The distress you feel when performing dhikr and reciting the Quran is an inevitable result of being engrossed in sins. Therefore, you must repent sincerely from all sins. If you repent with sincerity and resolve, Allah will make you taste the sweetness of intimate communion and will drive Satan away from you. For a sin is not committed against your will, but by your own choice. There must be a strong will and determination to abandon sins and repent from them, for whoever strives for the sake of Allah, He guides him to His ways, and Allah draws near to those who draw near to Him.