I went through something similar. I started keeping a journal. Also start a personal wiki, I use vimwiki and it's the best habit I ever developed -- it really helps to organize your thinking, you will also understand yourself better. Don't take a sabbatical unless you have an interest that consumes you, given the state your in you won't get anything done -- at best it will let you wander into something you decide on and at worst it will be a temporary escape.