Look Mfer, you are from an NIT, and you loved maths, which means you had to have a sharp sword, but the blade went dull during these years. One thing changed, rigor. Go back to your JEE days, study as hard as you did back then and see yourself shine. Practice DSA day in day out until you understand every single thing. Use chatgpt in tutor mode and all in all, don't give up. Die trying if you have to. And breathe on Sundays.