Sasha, I think you nailed it when you said she was mad at you because it's safe to be mad at you.
Kids act out with the people they know care and won't punish them for their feelings.
When I taught, my students came to me in my science room because I was a Special subjects teacher and that was how it worked.
My grade 4s had a very controlling classroom teacher who had her thumb on them all the time.
They would act out so badly when they came to me (and other spec. Sub. Teachers) because they knew they could do so in a safe space.
It could be difficult at times, but we managed.
Calm but firm, as Dandy said.
All will be well in time.