I realize that the GPA is very crucial if I want to get into law school

I have a problem ... I kinda just acted like a complete tard in High School, I am still in High School and stayed back because I messed up and goofed off so tho this is my fourth year in High School I will be here for another year... (mainly to take like three classes next year) I was wondering... If I load my next year with classes and really press myself to do good (including in this year) do you think its possible that I end my High School career with a good enough GPA?