Hello aspirant,

Just don't think negatively at all you did well till now and you can achieve many more in life. If you say it by luck also then to you studied a lot that's why you Mains went well. For Advanced just give your 100% learn everything you can and do your best rest else will be good. You can go below the following and prepare for the exam:

• Prepare a well-laid Plan. Draft a daily schedule.
• Get hold of the syllabus.
• Time management is a must.
• Understand basic concepts.
• Choose the right study material.
• Solve JEE Advanced question papers.
• Prepare your methods of learning
• FAQ preparation
• Keep a constant pace of learning
• Don't lose your patience
• Bon Appetite, stick to your proper health and diet.
• Do not attempt anything new in exam that you didn't prepare for.

Thank you