It is extremely scary to go up against a boss, @
Have Hope. Cold feet are understandable; I had them as well.
It's nice to know there's a no-retaliation policy in place, as it may deter the bully boss from doing anything to make the situation worse for them.
We've no control over what other people, including what the bully boss will or will not do. We can only hope that things go in our favor.
Fortunately, the person that handled my situation was honest, willing to review the information I'd brought them with an open mind, and also willing to explore in depth what was laid before them before making a decision.
In this particular instance it did go in my favor, but there's been another time or two that it did not. Then I had to decide if I was willing to stay in a toxic work environment, or if it was time to explore other options…
At any rate, the ball is rolling now and there's no turning back, so remind yourself to breathe (deep breathing exercises really help), and do your best to push the what-ifs away.
I'm still in your corner...