Assist please for a new inning…!!

Hiii, Sir/ma’am
I didn’t get through this prelims that is a little shocking because I had prepared for it but somewhere it remained down the line.
Hence I want to start again with double energy .my optional is Pub Ad. I wanted a Detailed suggestion about how to start again and specially way to study pub ad in effective manner and GS also Kindly help me out sir ,I don’t want to wait more . Time is really high and failures are knocking me hard :-(.. Please

Thank you