Emotional & Mental part of surgery

I read alot. I like to research every angle before I make a decision. The thing that has surprised me the most with surgery is the emotional and mental aspects that I have felt over any of the physical aspects. I feel more moody, not just cranky but easily annoyed or easily ticked off. On some days I feel fine, others I want to cry and then others I want to rip someone's head off. It's a serious roller coaster and probably not all attributed to after effects of the surgery. I have always been a pretty upbeat and optimistic person with very little modd swing issues but now I feel like I'm on a constant PMS ride, sometimes. Anyone else have these?