I'll answer your questions in the order you ask:
No problems, just relax and I'm sure you'll find it - we did!
Don't be so thorough - I'm sure you'll find it just where you least expected it!
From what you say, I'm not sure you're in the right field, what's the revision date on your map? You definitely don't have to cross any walls.
I didn't come in from the B6265, where are you coming from?
Shame you're having problems - you'd been doing so well too!
I'd definitely take the tent - camping can be so relaxinggggggggggggggg at this time of year.