How to get my mother to stop making me feel so bad?

I feel useless.
My mother makes me feel so low it's unbeilable.
It all started when we had a huge argument on holiday and ever since then she makes me feel terrible.
She'll bring up the past, she'll scream at me when im not doing or saying anything to her.
My sister gets away with murder in my house and it makes me want to pull my hair out.
She'll call me names like 'fat bastard' and she'll tell me to find a flat and move out because no one wants me here, she'll bring up other peoples children in our conversation saying she wished she had their daughter and not me.
But the worst is when she brings up my Nan that passed away 3 years a go, knowing how much I woreshiped the ground my nan walked on saying that when she was ill I done nothing for her, and considering I was only 12-13 at the time I done everything I could for my Nan and it makes me cry everytime she brings her up in arguments.
Also my mother was ill a few days a go.
I done everything I could to so help her in the house like washing and dishes, and a few minutes after she'll treat me like dirt.
She has always said that she'd choose my step dad over me anyday.
I've just finished my job and im in college and work in a salon on a friday, and she'll keep going onto me saying that I've never worked and I should get a job etc.

It makes me feel so useless it's horrible and makes me so sad.

But I dont know what to do. :'(

omg I frickn hate your mom sorry had to say that first off I want to say you are the only one who can judge yourself. Second off I was wondering have you ever told her how you feel when she talks like that to you?Maybe you need to talk to a family therapist so they will stop that or maybe you should forget your mom...nah thats to hard.

well have you tried talking to her and expressed your feelings?...if you hvnt then try that!..let me know how it goes

Whenever we talk it blows up into a huge argument of the past

Thats not fair to you at ALL. Your mom is the parent. She the adult. she should be acting like the adult. not screaming at you like a 4 year old. sometimes I have the same problem but you have to remember that your still the kid. you really shouldn't have to be treated like that. What you've said is absolutely ABSURD. Something really needs to change. and not from you. if you really feel that bad you have to tell someone . your dad. someone you trust. you know? your not useless. it's your mom who is. If she can't treat you properly then she shouldn't deserve to have you as a child.

my mom does that too
moms are biches
well not all
just make her feel bad :O

Try to talk to her and ask her why she is treating you like this and it is hurting you... and if that dont work then try ignoring her until you are 18 and old enough to move out ... and never speak to her again thats really mean of her... my mom is like that too.

The only good that can come from this is that when you become a parent you will know exactly how not to act, so thank your mom for making you a better person, the person that she can't seem to be.