3 year drop means you have done your syllabus well but you are lacking in motivation.
First, you have to believe in yourself. Watch some motivational videos and get yourself on track. Remember nothing is impossible. Everyone can achieve anything they desire in life.
Second, dont keep doing new things. Do your old notes and revise them well. Revision is the key to succed in neet, aiims and pgi pg exam.
Third, give a lot of grand tests. Give a grand test every week and check your weak subjects and revise them them. Subjectwise tests are useless. I would advice you to stay away from them.
Last make a time table and stick to it. Revise whole syllabus in the last 15–20 days also once to have an edge in exam and the confidence that you have done everything.
Always believe in yourself. Others opinions shouldn’t matter to you.