My mum is being so nasty to me!!?

do you guys think this is harsh.. my friend asked me to sew this bit of elastic onto a hat for her for dancing and i was sat downstairs innocently sewing it and i was trying to thread the needle and getting annoyed because i pricked myself and my mum comes downstairs and starts shouting STOP SULKING WHY ARE YOU TRYING TO SEW IT ASK ME INSTEAD OF SULKING. this made me really upset, usually if i would ask her to do it she would huff and puff! why is she being so nasty? shes like it all the time for me and never shows me any love at all, i tell her this and she says sorry and promises she will do different but she is cold towards me all the time! it makes me really sad and im crying now because i dont think she loves me. the other day she asked me what i wanted for christmas and i asked for some ugg boots and her and my dad both started screaming at me saying no because it will be my only present, whearas theyre happy to buy my brother one big thing and not me :( what can i do? i cant ask her to be nice to me again cos i tried the other night in the car saying she had been off with me all the time but it doesnt work :( please help? x