So I went for 20,000 KM checkup and found out the spark plugs were completely finished. Luckily I had 2 days of warranty left so got it changed for free.
I use Shell V Power 99% of the time because it's easily available. According to Honda, the reason why the plugs wore out prematurely is because of the fuel, and recommended Attock HOBC, which has, I think, total of 2 pumps in Islamabad.