Hello Meera,

First of all don't be too stressed out as it is never late to accomplish anything if you are dedicated enough. It is okay if you haven't prepared well in your 11th. You still got enough time to prepare. As of now don't waste your 12th and concentrate more in this year so that you can get more time to revise 11th after this. Instead of feeling like you've wasted a year just utilize this 12th and later coverup the 11th. You can definitely do it dear. All the best.

Hope this helps. Thank you.