Dear Aspirant,

This problem is very common and infact it used to happen to me all the time. The trick is don't just understand concepts try and implement those concepts then and there. Suppose you are studying centre of mass then you should practice questions related to it after you think you understood the concept. Don't keep that in your "will do it later" list. In Science there are a lot of numericals and you cannot master them unless you practice everyday. You can definitely prepare in 5 months. Just focus and stay consistent. Plan your day and don't loose hope. Take help if you need of your teachers/mentors. Do examples as well which are present in a book to make you understand the concept.

Hope this Helps!

Good Luck