You're still 18 and have a HUGE cushion for making up for all the time you've lost, don't stress it too much.
Feeling guilt over wasted time isn't going to do you any good now. This won't reflect on your CV AT ALL or your future prospects if you can make up for it in your bachelors, I can assure you of that.
Just keep your head down and give your best shot at JEE now