Complete A Work For A Deadline

There’s an upcoming annual prestigious contest for writers and I started working few months ago on a piece I wanted to submit.
At some point I reached a dead end (I know it’s a thought) and I stopped putting the time into further developing it because I kept telling myself that “I don’t know what to write next.”

With a month and a half to deadline, my prefrontal cortex still wants to make the deadline and submit my work, while my lower brain freaks out and says:

“There’s no way you can finish it by then.”
“You cannot hurry it if you don’t know what to write next.”
“Even if you will hurry and send something, it will be F minus work, so why bother.”

I am kind of new to SCS and couldn’t find a course that relates to writers here but I assume it’s all about what I am choosing to think, even though my lower brain is certain that “There’s no way you can finish it by then” is a simple fact of life, like gravity.

When doing models I could only so far come up with desired feelings and actions for an intentional model:

C= Submit a piece of writing in 45 days.
T= ?
F= Determined, On guard!
A= I don’t listen to my lower brain, I make a packed schedule every single day and force myself to write no matter what, I shut down every negative thought that rises up, I write whatever comes to me.
R= Even though I may hate every minute of it, I complete the best piece of work I can and submit it on time.

So I cannot find a though/s that will work for me and this whole model feels like a punishment, but maybe this is what Brooke talks about, feeling like ass, feeling discomfort and all that. Maybe this whole 45 days till deadline should feel terrible, as long as I will meet the deadline?

So, I would love some help with thoughts…