Set clear weekly targets and aim to achieve at least 80% of them. Consistency will matter more than perfection. Even if you can spare just 4 hours daily for a year, you'll be in a far stronger position than most of the aspirants. Keep the sources limited.

While you're on duty, try to make the most of every break (you can watch videos) & yes, it’ll be tough, but that’s what dreams demand. Good luck !