This means that OP needs to keep his dealings with bitcoin secret and not to allow his children or lousy relatives and friends to know that he own bitcoin if not he will get himself into trouble for violating the law.

I lived in a country where bitcoin was illegal and I was still buying and selling bitcoin via p2p trade, but we don't tell anyone that we are into bitcoin and that has become part of me currently because now it is is legalized I don't allow untrusted people to know that I am into bitcoin.

Pretty weird situation you are in, but I am guessing that even without a credit card, you could pay for online purchase one way or another through a digital wallet yes?

Check if Binance is not allowed within your country, if it is. Hop in, have yourself be verified such that it allows you to withdraw and deposit money, and then try P2P. Binance's got the safest P2P system out of every exchange out there cause they literally give you back the funds in no time soon as you report the person to be a scammer. In any case, try that. You should have a couple other people within your country or the next who could sell your bitcoin in exchange for your local currency.

I wouldn't suggest going to any other exchange nor "avenues of buying and selling cryptocurrencies" since this world's full of scammers at the bottom who would love to feed off of the scraps of the people who don't know better. Stick to a single option, like binance, no one's gonna hate you for it anyway.

Now it's easy to keep the transaction a secret because every purchase does not require a third party. No need to talk to anyone about the investment that is lived and he is enough to behave as usual. It is not easy to run investment if the state does not allow Bitcoin or Crypto but he can do it secretly. As most people say that being anonymous can actually protect the investment that is said to run in Bitcoin.

You part of the example because in your country Bitcoin is banned but the interest and desire to continue to invest makes you take that step. For him to be able to take steps like you did so that he can continue to invest even if the country forbids. Just how he tried to keep it a secret and did not talk to anyone about the investment he was running.