I Told My Mom I'd Move In with Her when I turn 18. How do I tell my dad?
For context, my parents have been divorced since I (17 F) was 5 years old. They would have fights with them only being verbal and not physical. My mother (46 F) got into a car crash the night she left, which left her unable to walk, talk, or eat properly without a stomach tube. She also lost part of her memory because the crash left her with a brain injury, so when it came to custody the court gave my father (49 M) full custody. My grandma, who was taking care of my mom, fought this decision the whole way through because she claimed my dad abused my mother, which isn't true from what I can remember. It wasn't until several years later did I get to see my mom again, where she gained partial custody of me with the court order being that I would visit every weekend, with the meeting spot being the half way point between where my mom and dad lived. (Which is only one state away). My mom also won a lawsuit against the company's truck that ran her over in the car accident.
Cut to now, my mother has had a full recovery from her accident and lives with my grandparents in a house she built for all of us, include a spare bedroom for my cousin. My cousin ran away from her family because of stuff I'd rather not discuss online, but I gave me an idea. You see, after you turn 18 the police can't take you back to your parent's house if you don't want to. Ever since my parent's divorce, my dad has been struggling more and more with keeping a house or a stable job. I've moved so many times, that I can't ever remember, with a lot of those places being motels. All the while, he was dating someone from the Philippines (they met on a dating app) and sending her money, he also introduced her to me over FaceTime. I wanted my dad to be happy, but at the same time hated how much he spent on flights and other stuff for her when we were already struggling with money. He then married her in her country while I was at my mom's to get his wife a green card. The whole time, I just avoided the situation, even though it bugged me a lot. I eventually told my mom, in the heat of the moment, that maybe I could just run away and live with her after I turn 18 and finish the school year. She took this in complete seriousness, and I don't know what to do. I partly do want to live with her because all of my mom's family lives in the same city where my mom is, while I've only ever since my dad's family once. Not only that, but I know she can support me and give me food, a place to wash my clothes, and my own bedroom. Thing's I don't have/and in limited supply at my dad's. Especially considering we live in a motel and his only job currently in Doordash. Up to now it was only the two of us, but with my stepmother here now I'm worried. She is a lovely lady, but I know I can't keep putting my life on hold, for other people. I still want to visit my dad, but I don't know how to break the news, he's never taken bad news well and it always leads to shouting.
Overall, I'm just asking, am I wrong for wanting to leave? And how do I tell this news to my dad? I'm also sorry if this is kinda all over the place.
Edit: Idk how I forgot to mention this, but the plan is that after I complete this upcoming year of high-school, then I'll move in with my mom, because I don't want to have a bunch on complications with school since I would be leave 3 months earlier to move to another state.