Although, it is NOT advisable to transact with crypto in a country where it is "illegal", the very nature of Blockchain (permissionless) allows anyone to access it at will. Laws/regulations can't be enforced on a decentralized network. Only on centralized exchanges and/or centralized wallet providers. What's stopping people from using crypto "under the radar"? Of course, expect to face fines or jail time if you're caught doing this. You'd need to decide whenever it's worth taking the risk or not.
OP should forget about big purchases like houses and expensive cars because his money comes from an illegal asset in his country. But no one can stop him from paying individuals in bitcoin and receiving goods and services in return. Also, no one can stop him from exchanging his bitcoin to fiat and using the cash however he sees fit.