Kicked out of home...did I overreact??

So My little brother who’s 13 stole my debit card, from my wallet that was IN MY ROOM and charged it up with games. This is the third time it happens with ME...it’s been countless times with my mom. She literally says its my fault because “I already know how he is” ...And I just lost it. I’m not working. I’m a single parent and struggling as it is. I called the cops because he NEEDS a fuckin awakening and because of that she kicked me out. She would rather defend and cover up his bs than straighten him up. He has stolen cell phones, cards, cash, games, bikes, he even broke into someones garage a stole a mini motorcycle before. This is enabling at its worst and now I will probably no longer have a relationship with my mother. The cop even pulled me outside and told me himself I should leave. He said it’s ridiculous how bad she is defending him and its only gonna get worse. He’s encouraging me to gtfo before shit gets worse with him. He said its completely insane how bad she is defending him. She told my dad I was victimizing myself to the officer and that I was my fault for “leaving things around” ...and also I must be “good on money anyway since i went out.” Somehow I still feel torn. Did I overreact? My sister who is older and my dad have sided with my mom but I just can’t seem to understand her rationale. Am I wrong for finally getting fed up and actually doing something about it this time?? He literally just did it to HER earlier this week but she simply says he has ADHD and can’t control it so she’s doing the best she can with counseling and psychiatry. Its been dozens of times. It is obviously not fuckin working but she still justifies his behavior. I’d be lying if I said if didn’t break my heart that she would rather kick me out and not have a relationship with me and her grandkids than to straighten him up. Why do I feel so torn?