History has shown us that the best preparation for both the SAT and ACT test is about 3 to 3 and 1/2 years of high school.
If you find yourself behind the curve a little because you did not pay attention, take notes, do you homework on time or received poor grade. Please use this opportunity to repeat the last 3 years - and do it right this time.
You will find that this method will increase your SAT and ACT scores immensely! It worked for me, and it only meant I had to stay in high school an extra eight years. And I did not have to spend any extra time in college.
Also, being your class Valedictorian is a big boost. Statistics show that colleges students who were their high school class valedictorian had better grades in college than student who were not valedictorians in high school. If you it does not look like you will be the validictorian, you might want to start over and try again.