Complex sentence: I had to relearn everything, how to walk, talk, eat, how to use the bathroom, how to care for myself and then there was the incessant pain, the physical pain of my body overcoming weakness and injury.
Split into simpler sentences: I had to relearn everything, How to walk, how to talk, how to eat, how to use the bathroom. How to care for myself, and then there was the incessant pain, the physical pain of my body overcoming weakness and injury.