Graduating early

So I'm 15 and a sophomore I like to say I'm mature for my age . I want to graduate next , meaning I graduate early @ the age of 16 . When I asked my mom if she would allow me to do it she proceeded to get mad at me . I am smart enough to do it and have enough time . She told me that I am wishing my life away , that I want to grow up to fast , that I wanted to do it just cause my boyfriend graduated this year , she doesn't want me to get on with my life so soon , and so on. The real reason I want to do it is because I want to go into vet school and where I live it's hard to get into vet school and I want to start it soon because I want to go ahead and get the schooling over with and start my career . Maybe I am trying to grow up to fast , or maybe my mom is just being stubborn . I need some advice please!!