Please don't  get demotivated just because you're facing difficulty  in one subject.

Clear you mind,do meditation or whatever make you feel relaxed, then pick a topic, read it, understand it ..solve it..if you couldn't solve it at first attempt,try one more time. See where you're making mistakes.

Try different approach. Don't get sad when you can't solve a problem,instead you should be motivated to solve it. I know during preparing for any competitive exam, every aspirant has to go through a lot. But only those achieve their goal who are hardworking and consistent in their preparation. Try these 4K approach..

KEEP your patience in solving ANY problem.

KEEP clearing your concepts,doubts.

KEEP practicing again and again.

KEEP solving previous year question paper.

If you're  still having difficulty then ask your teacher,friends to help. WATCH some video tutorials related to topics,download material from online platforms.

You can also click on this link below:-

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/articles/jee-main-preparation-tips-for-maths/amp&ved=2ahUKEwiej9LHzrT4AhXb9jgGHWg1BFkQFnoECEQQAQ&usg=AOvVaw2Fnwi80hhnP01UC3a6pk9E