It's no fun at all!!! A book that helped me with the emotions is The Happiness Trap. It's not an easy read and I'd guess I only absorbed maybe 15% to 20%, but even that helped me a lot. It talks about how emotions ebb, flow and cycle throughout the day, and how it's better to let them flow through then to try and fight them. Let them run their course and you can keep moving forward, but fight and suppress them and they come back bigger and nastier than before. It's also helpful to not see emotions as "good" and "bad", but as just part of life. We tend to chase "good" emotions like happiness while trying to bury "bad" emotions like sadness. But that's a rat race we can never win because of the cycling nature of emotions. So see them for what they are (a necessary part of us) and let them happen.
