Is my repentance the cause of sadness and distress after my prayers were initially answered?

You must continue with sincere repentance, adhering to God's law, and avoiding prohibitions. Sadness may be a whisper from Satan, so you should abandon it and continue on the path of righteousness. Sincere repentance transforms sadness into joy and tranquility, and eases affairs, as God Almighty says: "And whoever fears Allah - He will make for him from his affair ease." Continue on the path of righteousness and trust in God's management and have a good opinion of Him.