AITA for refusing to help with my stepdaughter because her mother won't let me take my own car to their place.

I will keep this brief because I just plain and simple can't take this shit anymore.<br><br>I am 43, my wife is 32. We married when her daughter was 5.<br><br>Her daughter is 10 now and I love her to death but I want her to understand she is not the reason for everything.<br><br>So we had a family meeting last night.<br><br>I wanted to buy something for my own collection and I wanted my wife to take me to the store because I wanted her to understand that "my" stuff is not her business.<br><br>I also wanted to ask if I could drive my own car to their house, not the family car, because they keep taking stuff from it.<br><br>So my wife, who is usually a voice of reason, told me I'm being unreasonable for asking her to take me to the store just because I don't want her in my stuff and also told her daughter that I wanted to spend time with "my" wife, as if I go to the store to spend time with her.<br><br>As we were leaving the house I asked her daughter to get her school bag because she forgets everything the last couple of weeks. <br><br>She started going on about "it's not my problem, just buy her a new bag if she forgets that much".<br><br>I told her that if she came into my room, she is responsible for that stuff and she started yelling at me for forcing her and saying I get off on making her uncomfortable in my room. <br><br>When we got home I told my wife I wasn't comfortable with her staying in the basement room connected to my office (which again, she is not allowed to be in). <br><br>She started calling me a cheating asshole who wants to get rid of her daughter because she overheard me telling a friend I want her to go to a boarding school. <br><br>I told my wife she needed to get her daughter before I left for work or I called the school and told them to wait 20 minutes before opening (the kids start at 7:30am). <br><br>She didn't give her daughter her college savings money for the bag so she started yelling at me for not letting her stay, cheating on her, forcing her to be uncomfortable and not letting her into my office.<br><br>AITA?