Why does the questioner feel that Allah's strength is no longer with him, and that Allah is displeased with him, despite his and his wife's commitment to acts of worship and avoidance of prohibitions after marriage, whereas he felt Allah's companionship and the facilitation of his worldly affairs before marriage, even though he was in contact with his current wife before their marriage?

Whoever repents with sincere repentance, Allah accepts his repentance and transforms his evil deeds into good deeds. You must have a good opinion of Allah, as He says: "I am as My servant expects Me to be." Allah accepts supplications and repentance and forgives sins. To strengthen your faith, reflect upon the Quran, read the Prophet's biography (Seerah), supplicate to Allah, persevere in night prayers and seeking forgiveness, and strive against your lower self, for Allah guides those who strive for His sake.