What my mom said really hurt me

I posted this in a different group, but everyone was being really mean to me. I just want to know how to fix things with my mom

My mom and my step dad recently got custody of my 4 year old step brother. I'm 18 and wasn't looking forward to having a child invading my living space. They took got him because his moms boyfriend or husband (don't know if they're married) was abusing him really bad. I know I should have been nicer to him but I found him really annoying. He constantly wanted to be all clingy to my mom and if she wasn't there he wanted to cling to me. He would come into my room at night because he was scared and I would kick him out. There was nothing to be scared of. He had a nightlight so he had no reason to be scared.

Today I had left my color pencils on the kitchen table and when I went back to the dining room he was using them. I asked why he was using my color pencils and he said he was drawing a picture for when he sees his mama. I was pissed that he just decided he could use my shit and I started picking them up and he whined that he needed to finish his picture for mommy so I told him he wasn't gonna see his mommy. He said he was and I rolled my eyes and told him his mommy isn't coming back, that she doesn't want him so his stupid picture doesn't mean anything and to leave my stuff alone. He started crying and my mom came to ask what was wrong. I went to my room. I knew she was gonna come and yell at me when he told her.

She came in my room and stared at me. I said I just told him the truth. She asked me if I remember when I stole her car when I was 16. I said yeah why. And then she said if I remembered when she caught me smoking weed. I just kept quiet. She said to me "I was mad at you for those things. Angry, but I have never been ashamed of you until now". The. She walked out of my room.... I wished she just yelled at me.... Because I have never felt more like a POS in my life...

Kay. I'm a POS. Got it.

I love how nobody on here cares about how I feel. Nobody ever wants to hear that their mom is ashamed of them... But I guess that doesn't matter..

Can people plz stop telling me how awful I am and just tell me how to make things right with my mom. That was the most hurtful thing shes ever said to me... And I don't want her to stay ashamed of me.