Yes. This just happened to me today.
It's Halloween today, and I was depending on my neighbor to go with me. We went together the last two years so I assumed she would come with me this year. It was 7 P.M., she was not home and was with her other friends. I got very angry and sad, and then I stopped and thought.
Is this really something to get angry about? Why am I making such a big deal? I'm sure she just forgot or wanted to hang out with her other friends.
I realized that this was not a big deal, and that I should stop and forget about it. Before, if this particular event happened, I would have started to jump to conclusions saying that she must hate me or something, or found that I was a loser. Sure, that could be true, but we've been friends for years and it was unreasonable to say so, especially if I have done nothing wrong.
I am not sure of your situation, but stop and think of it and what happened. Did he simply forget or something? How long have you been planning the cakes? (If it was planned long ago; he should have remembered, given you the correct number, or called you or something) Perhaps this was actually a big deal, and you have every right to be mad.
I'm pretty sure stopping and thinking of the situation will not help everyone, so it may not help you as it is my own way of solving my difficulty with tolerating problems.