Hey, so, I'm not a doctor. Because of the symptoms, I'm worried that this could be something pretty serious, like undiagnosed diabetes. There is a type that can develop in teen years. Also, I've known dieters with problems similar to what you've described. A lot of people experience significant problems with mood, memory, temperature, muscle weakness and shaking if they aren't getting the food they need.
I know how difficult it is to go against the wishes of a parent, but I highly suggest you get to whatever medical professional is available to you, such as a school nurse. If a school official expresses concern, your mom may feel enough guilt or shame or social motivation to pursue some sort of solution.
Please do what you can. The symptoms you mention can be related to serious but relatively straightforward to treat illnesses that cause more damage over time if untreated. You deserve better than suffering and not knowing. Please do what you can to get some care.