If there isn't any sort of bitcoin service that you can use in your country for paying bills, then you're out of luck. You can simply do what most bitcoin-only people do though; sell a bit of bitcoin each month solely for your bills.
Please, what do you advise I do in other to hold at least 80% of my salary in bitcoin?
Use your salary to buy bitcoin after every paycheck, and leave a bit for your bills. It's that simple.