Dear Tom
I'm sorry to hear this thing,but here are some suggestions about how to study for you.First,you must follow the teacher in class and take notes fast,it's important for you to understand these knowledge points,and then the exercise is necessary,because the knowledge need to be remmbered repeatly.What's more,you can remind these knowledge points by some ways,for instance,make some cards which write some knowledge points on them with you wherever you go.Last,don't stay up late,it's important for your body and study.
I hope you can learn better after reading this letter.
Best wishes
Yours
Lihua