My dad wife has been a real b+++++ to me. Im 14 and my dad has a court order that i have to go over there every other weekend. don't get me wrong i love to see my dad but then i have to see her. she has been in our life for about 3 years and it has been this way since they have been married. She is really immature and has no self confidence. She has yelled at my sister worse than my dad and mom yelled at her together. (btw my sister is 11)Also she threw my phone and it almost broke(half the keys froze) She has no children of her own. Me and my sister have gone to therapy together and with my dad. My dad knows that we don't like her. She has cause so much stress for my sister and me over the summer break we went on a trip w/ her and my dad and she was really mean because of that my sister had problems eating for 8 weeks and at some times didn't eat at all. For me she has put so much stress on me that it is hard to pay attention and i some times suffer from anxiety issues. So how do i deal with my stress along with my step mom?
also my dad is against just doing something with just my sister, me and him.
any help would be great thanks

i have talked to her and my dad and her we have had family meeting my dad thinks that she has done nothing wrong.
she just moved to my state about the time she start to see my dad so after she moved here they meet at a wedding my parent has been divorsed about 5 years and my mom is happy and re married
i tell my mom everything that goes on at my dad's house and every thing that she does. and yes my dad is stuborn!