My dude. That is not healthy. Please don't destroy your health for this job, it is not worth it. The leadership at this company are horribly self-centered and they have lead this project into a hole in the ground by their gross incompetence and poor planning. Your health and well-being are not worth the meager pay you are getting. And I know its meager because you mentioned having to negotiate pay for this project, which tells me you are not getting paid what you're worth already.
You are not the one who waited until the last minute to plan project tasks; that was management.
You are not the one who thought we could get 18 months of work done in 2 months; that was management.
You are not the one who short staffed the project team, causing all of us to work through lunch fort he past month and often pull 10 hour days; that was management.
You are not the one who will suffer financial consequences if we don't get done in time; that will be management.
Don't work harder than you are getting paid. Don't work harder just so the CEO can meet his bonus targets for this quarter. If he's so concerned about that, he can come down here and pick up a shovel.