Adrien's life became boring and meaningless after that night when he confessed his feelings to Hector. He kept doing the same exact thing every single day which made all his days look the same and meaningless.
He wakes up in the morning and only comes out of the room when he seriously needs to eat and comes back running to his chamber right after bringing some food from the kitchen since none of the maids or guards seem to care about him even the brodalisques who are in very low position compared to him get treated and respected way better than him even though he is the prince.
Also, his brother Arthur the only person who used to care about him and make sure he eats and sleeps well stopped caring completely about him after their fight in the garden when Arthur called Hector a low-life.