My family is taunting me because I am bullied

Some time ago I posted that I had been bullied a lot over my weight and some other irrelevant things. A lot of people told me to tell some one about it and I did. The teachers took it.. Semi-serious and told him to stop (I dont know because they talked to him privately) He has only done small things that I don't care about or ignore you could say I'm feeling better until a day at home when my mother was pissed at my little brother (he's 12) for taking her makeup and smothering it all over a shirt. She was starting to cry over the shirt and my brother and her kept saying words such as "Bitch whore" to each other and I wanted to go outside to avoid this. But I couldn't be that lucky she dragged me into the argument and the thing was for some reason I have always laughed when I feel uncomfortable or I don't know what to do it's sort of when some one falls and you laugh but you don't want to. So she shows the shirt and I feel that feeling of wanting to laugh put hold it in but when they continue and my mother keeps taking me as an "Good example" My brother jokes about a vine and that makes me smile. My mother ignores his insult now to call me bad words she asks me why I'm smiling and if I was smiling when I got bullied. Because she can smile when I'm getting bullied she can encourage him to bully me and how I will deserve it. This actually made me tear up immediately not because of what she said but because she targeted me after I smiled and could not care less that my brother was making inappropriate jokes about my mother and a person she was dating. I become really frustrated and angry so I walk out of the room wanting to leave but she tells me to come back and tells me "Don't you dare cry" over and over.. She continues and when it ends my brother apologizes later but I simply refuse this wasn't my fault. But she thought so.. She refused to speak to me the whole day and the next day she told me she needed time to heal and it would take days. Really alright.. I kept silent she then apologized to my brother and they became semi-friends she kept giving me dirty looks and I apologized too she nodded and said "Yes that's right" I don't want to dramatic but this is actually worse than my school bully I'd rather be bullied entire day at school than be mentally abused by my own family because my own bedroom is the only place I can feel safety and if that place is removed then I wont have any place to feel.. At home at..

I'm not sure what to do and I don't think this is so serious as she makes comments like this now and then but this has moment has kept replaying it's self in my mind and I've started to think it's my fault.. I just want some reassurance please.. And I can't talk to any one about it