Cold tap not Releasing Water and Cannot Access Washer Drainage and wastage systems and plumbing help, advice and answers

[Oscarboat]

Hi,

So my cold tap has stopped producing water when i turn it. I am trying to get at the washer and essentially take the whole think apart with the aim of fixing it. However, I can't seem to actually get to the washer. Can anyone give me advice on what I need to unscrew next? I have tried the hex with my monkey wrench, but it doesn't seem to give.

Thanks