When I was studying to pass university exams I've researched a lot to find out how to study effectively and below I share my methods which may work for u too:
-Set a simple and precise goals. Even you can't reach the deadline it will help you to study faster because you by setting simple goals you will have cleaner mind to study faster.
Try to keep your study area separate from the resting or leisure areas. Find out what time is good for you to study and what time is good for leisure which will increase effectiveness.
In order to motivate yourself ask why are you even studying at the first place and what will happen if you won't. Keep that in mind at all times to get inspired.
-Limit your distractions. Ask your parents to not disturb you during the study hours,turn off social media notifications on your smartphone,study in a calm place etc.
My last point is that you should try to find a flow in whatever you are studying : A flow state is achieved when you do a task that is optimally difficult and also achievable at the same time. So set yourself challenges that are hard yet achievable this will keep you engaged in the subject. And always remember to take short breaks to not make your brain exhausted)
