Need Help Boosting My WiFi Signal!

Hey everyone! I'm really struggling with my Internet situation at home. Unfortunately, I don't have much control over the router, and the people I'm living with are not very tech-savvy. They've disabled the 2.4GHz band, which is the only way I can get a signal in my attic, and the 5GHz signal just doesn't reach that far. Since this change, I'm completely cut off from the Internet, which really impacts my ability to work and study, especially since I also have some health issues to contend with. I'm stuck here for now and can't find another place to live. Do you think a WiFi booster or extender would help me pick up that 5GHz signal? I'm looking for something straightforward to set up. Thanks for any suggestions!