How do I deal with my grandmother?

I’m 18 and a reserved person and don’t let people into my “bubble” expect for my Dad, brother, and 5 dogs. Due to unforeseen circumstances, I have to live with my family again in my grandmother’s house. I’m a dog trainer and my dogs behave fine. She complains if my dogs just bark while I’m playing with them. She never sees my dogs though because they’re in the basement with me. I can’t remember ever liking my grandmother much. I have a job, dogs to train, a life to live, and school to attend. Financially I can't afford to move so I'm stuck here. A few days ago, my Dad told her I’d go out to shop with her without confirming it with me. I told her I wasn’t going and she got upset (my Dad says she’s just “hurt”). She wanted to buy me clothes I try to smile and talk to her. Sometimes she’ll say nothing back and I feel like it’s a waste of my time. My Dad is siding with her. I feel like I can only count on my brother. How can I deal with her, please her, and still keep my life going?