I hate my brother

My brother is 18 years old almost 19 and he’s one of the most awful people I have ever met. On Halloween, my dad asked him to leave after he invited his girlfriend over without telling anyone, AND THEY WERE IN MY ROOM?? A few days before this, he pressured me to give home $560 so he could invest all of it. He reassured me that even if the investment failed, he would still pay me back, so I agreed. Fast forward a few weeks later, he got fired from him job and the investment failed miserably. I asked him to give me the money back and he started swearing at me, treating me horribly, and also threatened to fight me. I let my mom know, hoping she would care, but no. She started letting him live here because “he’s struggling and needs help”. A few days later, he brought his girlfriend over (who is 15 btw) after my mom asked him not to, so he got kicked out. A few weeks later, he asked to spend one night at my mom’s house again, and she gave in. He left in the morning the next day so my mom wanted to talk to me about the situation. I told her that I have no opinion on this since it is her house, we agreed that everyone wants him downstairs. We also talked about if he disrespects anyone here, he will have to leave. When he came back about an hour later, my mom talked to him about getting a job. He did not like that at all. He started calling her names and slammed the door on his way out. My mom told me that he won’t be living here. Literally 2 days later, he came by. I texted my mom asking why he’s here, she called me and explained that she’s giving him another chance. I just can’t believe that he’s back after 2 days and that my mom completely lied to me and let him back. I feel physically sick when he’s around. He has punched me in the face multiple times and he gets so angry very quickly. He’s a terror to be around. I could very well be over reacting, but what are your thoughts?