Do go in on Monday, if you don’t you are unable to defend yourself. Do just close your computer right now and go to bed. If a manager has unreasonable deadlines and other staff are not doing their jobs that’s on them, and it. Absolutely is NOT your responsibility to destroy your work life balance to make up for other peoples failures. If you don’t have a major stake in this project/company you should absolutely not be overworking and stressing yourself out this much, this will lead to burnout. If you feel like you are being strongly pressured into overworking yourself like this regularly it’s time to start looking for another position.