This year is an exceptional case as students cannot learn properly still due to technological advances, we somehow managed to learn a lot through online classes, e-books, etc.
You are closer to the time when you will be facing board exams. So, I would like you to get organised and create a revision schedule which can help you study smarter and learn what you don't know, dont revise one thing a lot of times and skip others.
Practice past year papers and get familiar with the question paper layout. Get through your like mock test given online or offline and check where you lost marks.
Do group studies often, explain others, it will help you know yourself.
Last but not least, take care of yourself. Proper food, rest, exercise is also essential. Don't stress too much, talk to your fellow mates, family and friends sometimes.
Good luck!