My mum is a psycho. Helllppp!!!?

Yesterday at 830 she tld me to wake up to help her make food for a BBQ we were going to. But I hd bad headache so I told her no I can't and to go away, then she called me selfish and lazy and say I never help her, so i said woteva and she called me a little cow and hit my ankle reallly hard. So I yelled at her and called her a pyscho. Later on she started punching at me and saying "You started it". What do I do??