It's not joking right? Let me us know your address were funded 8000BTC. if you able to given a proof by sign message so congrats, you're one the most lucky on this planet.
There is many way yo make your money be fiat money. I just trying with keywords " Exchanges in malaysia, so i got refference : https://www.buybitcoinworldwide.com/malaysia/ " I see a popular exchanges those listed. did you trying? You can do for daily withdrawal for max limit.