Help - my book is being hijacked.

Day ____ (I won't say) of getting a submission ready.
Yep, my submission is being hijacked by my characters. I'm happily editing along when the plot takes a lefty, then a righty, then a u turn. What the...! Now, I have to go back and re-think this sucker.
I REALLY need to get this submission ready. I'm feeling the pressure to have it GONE! But I can't let it go until I think it's good enough for my beta readers to check over. As I've previously stated I seriously suck at grammar. I think it's the fact I'm an Aussie trying to write in the US market and I'm doubting myself at every turn.
But the story has some twists and turns and hidden agendas that are creeping out - thanks Warden! Yeah, you know who you are - just because you are the controller of my hero doesn't mean you can twist me to suit your needs. No sir'ie ma'am. I'm gonna take back my power and pull you into line!
I sound insane and yes, you would be correct. But I need to write this down - to trigger my mojo to overpower 'Gina hard-face beeatch' as I've started calling the Warden. To tell my brain to get on with it.
I'm back!