I think i screwed up my life?

im still a freshmen and im suppose to be a sophmore this year and next year im suppose to be a junior i have 21.45 credits i only failed 4 classes this year and im goin to summer school i just failed my algebra regents and global regents i have no idea what i can do to be a 4 year graudate im not the brightest person i cnt study for sheit what can i do 2 help my self do good in school and succeed in my highschool life?