Gosh, Heidi, I'm so sorry! I wish you were closer, I'd run you to the store, or better yet...you could stay with us.

I am willing to bet that your mom has no idea what you are dealing with. Keep trying to talk to her. Just tell her that you feel left out, and that you literally have ver little to eat this week! She won't want you in that situation.

I would also alert her to the way your sisters are treating you. She's probably too busy to notice what's going on. She'll help you, just keep trying to communicate with her.