Feeling really anxious

I have had anxiety for over 10 years. I months a go I come of my medicine. But this morning my brother came done the stairs and starting kicking of.  He started to though thing and try and nock my dad out of his chair. My brother is 15. He then starting. Hitting my dad and my dad had to defend himself. My dad has MS so he can't hold my brother or restrain him because he isn't strong enough. I'm not strong enough. I then said I was going to call the police because it go so bad. Dad also was going to. But I'm  scared that he is going to come home and start kicking if again. (We didn't because I was scared of what he was going to do if I did ) This happens all the time. But normally my mum is at home but she wasn't. I just don't know what to do. I'm so shaken up at it 7.36 on at night and I'm still feeling anxious.