My mom makes me feel like a piece of shit

So I'm 19, and my sister is 15. My sister gets favorited by literally everyone. My mom, grandparents, uncle, aunt, and even my siblings. I'm like shunned by them or something, and I honestly don't know what I ever did. I'm crying right now as I type this because I feel like I'm worth nothing. That's how my own family treats me. They don't listen to me when I talk. They treat me like an annoyance. They cut me off. My words don't mean anything. When my sister says mean stuff to me they laugh at it and encourage it, but when I say mean things to her they get on to me and "I shouldn't say that stuff" blah blah blah. Just a few minutes ago I was starving and went to get a $1 TV dinner from the freezer. My mom says "WHAT ARE YOU DOING? THOSE ARE SARAH'S. (My sisters). (There's like 10 of them) I say "mom, I'm hungry and there isn't anything else to eat, besides she eats breakfast and lunch at school, this is all I'll have today." Then she says "No. Those are Sarah's. I don't have to support you. I don't even want you to live here." (Oh I live in a shed, btw, while my sister took my room.) (Yes, I have a part time job. I just moved back to my moms, and working on getting a second job.) so now I'm laying in my shed, crying, and starving, feeling worthless because my mom won't let me have one of my sisters fucking $1 TV dinners. I absolutely hate it here.