D: hmmm. To be honest it really is up to you. I would still be ridiculously upset and would cancel my flight and send her a grumpy email so she really understands and etc but I tend to be rather emotional in how I deal with situations like this to help show that they really hurt me.
If you know you'll regret the message then I don't know if you need to send one. Perhaps for you an in person meeting will be better? And then you can hammer it home there. I can tell you really love your mom

it just sucks that she did something like this

(I'm glad you have your aunt fighting for you too)