Hi Anshul, first of all don't be disheartened. There is nothing impossible. You may not be able to solve the questions, due to your lack of interest or concentration. If your basics are strong, then you will feel confident about the subjects and be able to solve all the questions. So, my first suggestion is, make your basics strong and try to study your subjects, chapters with full of interest. 

You can try one shot videos for that particular topic/chapter, and then try to solve the NCERT questions and then if you are a JEE aspirant then follow our JEE pe JEET series. Believe me you will find it easy. For your reference, I am putting here the video link :

https://www.youtube.com/watch?v=1r6yLUKc8yc&t=2441s

https://www.youtube.com/watch?v=7PonbK7i0nU

https://www.youtube.com/playlist?list=PLCzaIJYXP5YdD-nMkUNAKq3PAeBDVV23S

All the very Best!!