I often get upset during and after my dreams, too. I think it is very common. I once dreamed I accidently killed a cat and it bothered me for days!

The worst is when you dream someone you know has done something terrible to you or hurt your feelings and you actually wake up angry with them or not wanting to be around them. You feel bad because you know they have'nt really done anything wrong and it does'nt make any logical sense to be upset with them but you can't help it.
Meanwhile, the poor other person has no idea what they did!