3 yo demons?

My toddler has always been pretty easygoing but in the past month has morphed into a toy-throwing, infernal screeching demon. She’s not sick or anything. Sleeping fine. Just an absolute terror. She’s almost 3. I’m due with no. 2 in 2 weeks and am terrified it will get worse. Are we really in for an entire year of this? I want to die by 9 am every morning.