Take regular breaks. Go for walks. Meet some friends.
When I was about to finish my last (and first) big game, I didn't do any of those things and it let me into getting sleeping problems and all sorts of other stress related problems.
So take care of yourself.
Aside from that, try to break down your tasks into smaller bits and work on those small things. I have a giant piece of paper with sticky notes on my wall and each note was one task. It helped me to stay on track and stay motivated, because you're constantly removing things.
The last thing: If your project is this close to being done, avoid the temptation of adding completely new stuff to it. Your pile of tasks should decrease with every workday and not grow bigger.
But as I said, take care of yourself, seriously.