It's great when practical things come along to test us. It's really easy to get carried away with the belief we have surmounted all problems and emotions and that has to be tested.
What you should know is it doesn't matter what you do or what happens. You believe you have control, but you don't, not in any respect. That doesn't mean you should act irresponsibly, or not act at all, but you should be happy to accept any consequences from all actions or the action of passivity.
So, if you don't speak out then accept the anger, frustration, guilt that will come from it. Accept it because that is an inevitable consequence of a fixed path. If you speak out and get sacked then that is simply what was going to happen anyway, accept the changes, the grief, the hurt, the anger in the same way.
There are an infinite number of apparent choices, but ultimately there is only one that can ever be taken and that's the one you were always going to take.
I had a similar issue and left my job without any job to go to. I grieved for my status and income even though I believed I was in stillness. I started wondering if I should have left and worried about the future.
The reality is it doesn't matter and I learned that. It doesn't matter if you end up destitute on the streets. Obviously that isn't a goal
whatever action you make is the action you will make.
I often liken it to stepping on an aircraft. Once you have stepped aboard then there is no un stepping. The plane might land safely or crash in a blazing fireball, but worrying about it won't make a damned bit of difference. Sit back and realise what will be, will be.