Keep slogging, every single day.
I'm in a similar situation. I agreed to turn in a book every 7 months.
I'll pause for you all to gasp, point, and laugh.
Normally I say 8 months is my minimum, but this was a phone call (aagh) with the owner of Henery, and I had to convince her I could write to spec. (My agent knows I can, but, hey, I understand. She didn't know me from Adam.) I got the strongest feeling that I should *not* say 8 months. So I signed a contract for 3 books at 7 months each. I wanted this contract. I knew what I was getting into. Only because this is for my existing series can I do this. I know the characters.
I'm a little fried, but I have to do this, so even when I'm whipped from the Day Job and no mojo is forthcoming, I write every single night.
Flatness and emptiness can be spiced up in edits.
Good luck. We are sisters in exhaustion.