I highly recommend getting some books on dialectical behavior therapy/cognitive behavioral therapy. It's used to treat, among other things, borderline personality disorder, which frequently involves uncontrolled emotional responses.
I have had problems with this in the past - and like you, I get extremely grumpy about plans being changed. I've learned to use DBT/CBT to deal and it's had an enormously positive impact on all my personal relationships.
I realize I sound like a marketer, but these techniques have really made a huge difference for me!