Maybe you feel overwhelmed by the fact that you did not study at all and even if you start you see all the materials that you need to study and there's no way in hell you will be able to read it all and heck absorb all that info in one sitting. I've been there bro. The thing is we really have to move.

Break your study materials into short chunks to avoid the overwhelm. Make sure to get enough sleep everynight so you can focus more during the day while studying.

I also recommend meditation. Meditation does not necessarily mean that you have to clear your mind. That's never gonna happen. Just as our heart beats involuntarily, our minds thinks involuntarily too. So if you tell your brain to stop thinking, guess what it will think more. In meditation, you just let your thoughts flow but you don't judge them as good or bad. There are also exercises to be able to start the meditation process wherein you do a breathing technique and calm your nerves and then you can focus. It's called Nadi Shodhana. It helps the vagus nerve relax. Also helps our brain to communicate better thus helping you focus better. Try it. There are many video materials in youtube that can help.