Bitcoin not related to fiat currency, I don't know which wallet you're using but its really of the exchanger.
I guess you're using coinbase.com which is not recommend.
Find another wallet to store your bitcoin and exchange your bitcoin locally or using person-to-person trade.
To follow on with a few more question, could you please expand. 1)
When you say "Bitcoin not related to fiat currency" what do you mean?
2) "I guess you're using coinbase.com which is not recommended" - I
initially tried with those guys but their website was appaling so
couldn't even verify my identity. So no. But out of interest, why are
they not recommended? 3) Re. "find another wallet", would you
recommend a wallet that sits on my computer, or phone, and what is the
best method for P2P exchange? How to go about it? –
i'm not fluent in english but i'll try my best!
1- Bitcoin not related to fiat currency, I thought you were talking about bitcoin core and transactions fee. which is not possible to lose bitcoins or even turning your bitcoins to any fiat currency.
2- coinbase isn't recommended because they don't provides full access to bitcoins. its just like PayPal. Your bitcoins in there are just bunch of numbers. And they are custodial Bitcoin wallet.
3- I recommend you to install Bitcoin-core from bitcoin.org but if you don't want to download the whole blockchain(145 GB) and your usage for bitcoin is just simple. You can use blockchain.info they are non-custodial bitcoin wallet and gives you full access to your bitcoins , nobody can track your account and no verification needed.