Books that can help you understand emotion as energy:
1-Letting Go: The Pathway of Surrender" by David R. Hawkins.
2-The Power of Now: A Guide to Spiritual Enlightenment by Eckhart Tolle or Practicing the power of now for same author.
Here is a link to all my meditations these will help you in the process of understanding your emotions. Meditations and Mindfulness.
Note:
I choose these two books because they were the ones I read in the beginning of my journey and I still re-read parts of them now. I always find truth in them.