who's fault?

Since TZ is assigned to this current project, TZ have sacrificed his gym time, his regular meal time, his time with his friends and worst case his weekends. What is the main reason of TZ loses all of these?

1. The sales team has committed an extremely aggressive timeline / schedule.

2. The team has a poor planning on resources allocation.

3. The customers do not have a good idea of what they wants.

4. The development team just do not have a clear picture of how much they need to deliver

5. Message was not convey clearly to the working level.

6. There are so many dependencies from external to the project.

Now, the impact has arisen. Everyone is so stress cause the deadline is approaching... Everyone is racing against time to cover the earlier lost. How much can we cover for the lost of time... What else can it be done with management and customers insist to stay with the deadline?

I was upset as i was assigned to this project with the expectation to fix this project which i don't think it could be fixed given the resources have already exhausted, the project manager is struggling to survive, customers are squeezing and the management is insisting with their decision.

So what else can i do?