All thoughts feelings and actions are a choice. For every thought there is an action and feeling, for every feeling there is an action and thought, for every action there is a feeling and a thought. They are all choices. Many of those choices are subconscious (As is 97% of our existence). The reason solitary confinement is torture is because people do not spend enough time in the shadows. That is why a monk can spend 75 years in a cave alone and be 100% satisfied. We are mostly shadows. Shine a light on that shit with some meditation.

“All of humanity's problems stem from man's inability to sit quietly in a room alone.”
― Blaise Pascal, Pensées