Hey there

It's a common problem don't worry about it. See time tables which are made by students even though they are made with very good precision are mostly not followed as we all have different moods and different works to do at different times and they come up at random. So instead of making a time table which says at a particular time you have to do this you can take a Target for a day that will be more beneficial.

Check the link for complete preparation tips

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/articles/jee-main-preparation-tips/amp&ved=2ahUKEwiLz8iEwdTpAhVUzDgGHSaPD-cQFjAAegQIBhAB&usg=AOvVaw3GSa8oPTbvFl7CX28keJA1&ampcf=1

Good luck