Hello Babegirl,
This is a very difficult situation. Dysfunctional family matters are always tough to deal with and I can understand your pain. I agree with Tammie that your mother must have been at the end of her teather to say things like that, but is your mother all right? She must be under a lot of strain.
Remember that sometimes it´s a good idea to give families a break, a cooling down time, and maybe see some help to let go of your mother´s behaviour and to understand that what she says does not reflect so much who you are, but how she is feeling right now.
Morning Glory is right about ACA. You can get a lot of help there. But please let us know how you and your brother are doing, OK?
I wish you all the best.