As it's your first 600, you can try ride it as an anti-social audax. Keep faffing and chatting to a minimum, bounce controls, eat on the move etc.
Cutting down faffing time really does increase your time cushion, however it's not as much fun, especially for YACFers, as there's so many people to chat to at controls.
Alternatively get someone to take you under their wing. My first 600, Martin/Zoom showed me the ropes, and without his help, I doubt I'd have got round in time. I'm sure there are plenty of people here who can shepherd you round the BCM.