Hello there!
First of all relax.
Its okay to have a fear of exam and success at this turning point of your life.
Here are few tips that can help you boost your confidence-
1. Study well not quantitively but qualitatively.
2. Read well and learn your concepts well.
3. Take frequent study breaks.
4. Shun fear of failure.
5. Solve as much MCQs as you can.
6. Prepare well and take guidance from teacher.
Good Luck!

Hello student

hope you are doing good . Firslty i would like to strongly say no one is weak ,dont justify your lack of hardwork ,dedication ,determination by this word. It is a word used by people who fails . One thing you should to acheive somethinigs is try ,try and try without thinking the results. For jee mains ,first clear with your basics fundamentals ,go through ncerts and think a lot on each small concept to get it clear . Then join a coaching to know the hacks of questions to solve in less time , go through assignments and regular mocks. Do little but do with consistency you will achieve your goal

Hope you found this answer informative. Best wishes for your future