Any step kid advice needed. 5 yo and 4 yo

- dont listen to only me

- treat me like a pile of shit

- hit their 11 month old brother

- pull the baby down to the floor

And they do that when they know im busy making lunch or i need to help out my husband for a quick second fixing up the house

My hair is falling out i stress so hard when they are here. Im 15 weeks pregnant and i feel like they will cause a miscarriage. I dont know what to do. Im ready to divorce bc of them. I dont care that its harsh. They are the reason.