Me: We need to have a developer on our core product

*We fork our core product from a private repo for new projects

Management: No.

Me: But imma die 5years early from stress and anger overdose of fixing the same problems over and over again in every new project we do and still hit deadlines which didn't account for them when we could fix them once and maintain our core product

Management: everything is fine. Lalalalalala

Me: *wonder why every senior dev has left in last few years*

Don't push yourself too hard dude. If it were me, I'd let the project run over, and let that speak for itself. When management decides to come down on you, calmly point out that you responsibly requested additional resources and that request was denied. That said I am prone to burnout and this has become my response. Further, the last company I worked for expected me to work 'reasonable' unpaid overtime.... Reasonable to them was often 10+ hours on an already 40 hour week. No time off in lieu (illegal here in aus), nothing, not even a thank you. Just a 'Ima fuck you up the ass sideways with a rusty pitchfork' contractual obligation...