Wow. I am angry for you.

How your coach handled things (especially bringing in some one else) seems very childish. I don't know why people think that it is helpful to kick you when you are down, when all you need is support.
When people have done this to me... it helps in a way, but it also, back fires for that person. I tend to feed on that anger, but I also, cut them out of my life. Her being your coach, would make this difficult.
I think you did the right thing in not responding when you are overwhelmed by the anger.
Once I get some distance from these feelings, I am able to look at it objective from their point of view. But it takes time, and unfortunately, I never let those people get close to me again.
I hope venting helps. And you can handle things better than I do.
Try to remember that it says more about them than it does about you.