my ex has lost it

Well, i think my ex is losing it. I was helping her tonight like I always do, and she asked me to write a letter for my daughter's new teacher at school. I agreed, and I started writing it. She was dictating to me, and i tried to make a suggestion about some words, and she completely lost it. She starting swearing at me, and told me I have nothing to do with my daughter's future. I am hurt, angry, and ready to do something drastic.