As others have said, key at this point is going to be to
prioritize in relation to business needs. As hard as that all will be, the process will only get more difficult the longer you wait. I'd also suggest one thing you prioritize personally for yourself whatever happens is eight hours of sleep every night. :-)
As other have also said, you're also going to have to tailor the way you present the message about the facts (i.e. the "alarm") to your current organization's culture and your specific situation in it. You'll need to keep in mind your own talents/resources and current limitations in developing a message or plan (see also "Dunning–Kruger effect" for risks on that). Talents/resources and limitations include your own ability to present a message and what help you can rely on from the rest of the organization to develop a message and present it based on what your coworkers, manager, and management chain value.
If you eventually want to reflect on the larger issues that may have gotten you to this unfortunate situation and what your company can do better in the mid-term and long-term, here is a reading list I put together that includes multiple books on software engineering management as well as broader surrounding issues -- including a great book by Matthew Walker on the importance of adequate good sleep for everyone in an organization:
https://github.com/pdfernhout/High-Performance-Organizations...
One item from there:
"Why Deadlines Need to Drop Dead"
by Eric Elliott
https://medium.com/javascript-scene/why-deadlines-need-to-dr...
"Deadlines are incredibly destructive to team productivity and morale. The #1 challenge software developers face is unrealistic expectations. Can we motivate & push without arbitrary deadlines? You can lead teams without deadlines. You can still deliver code quickly. You can still ship in time for Christmas. But you’ll be dealing with a different management framework. One that puts the deadline pressure on product managers rather than developers. ... The point here is that instead of trying to build out the CEO’s ideal vision of the product you’re bringing to market, you build out a beautiful stepping stone on the way towards that vision. In place of arbitrary deadlines, you deliver consistent, steady progress."
Eric Elliott advocates for the Marketing department creating each hype cycle for what is already finished and tested.