How do you communicate to a mom who doesnt listen and wont understand?? help me please im desperate?

Im a volleyball player my mom is like a size 4 she wont say it but se thinks im fat cuz i take after my dad side who have more curves im 6 ft but she's been putting me on diets and forcing me to work out over time. Rescently she's making me work with the track team while my former volleyball couch has offered to help me on my key weak areas but I dont now how to communicate with her anymore she's a talker not a listener how do i communicate without breaking down