Dear student,
having focus on the goal is very crucial to crack JEE. Solving and practising problems will give you a lot of confidence.Do not get discouraged if you are not able to solve some type of questions, just keep practising and as the saying goes practising makes man perfect.
make a schedule for each day when you can study and be disciplined to follow it and study for atleast 2 hours a day and do refer to notes and be upto date.It will give you huge boost and your confidence level will increase.
all the best !!