Improving math to 750?

Hi guys! I took October and December, and got 660 and 680 in math. I’m good at English, I just need to improve to a 750 or above. Please help— how much time should I put in? Is it possible before March ? I’m taking school-day (March 25) and March 8th. Should I take both? Advice is appreciated, I feel so lost and unmotivated after such a dismal change from October to December.