The script suck and apparently now it's my fault as the editor

Just need to get this off my chest, but I am having such a bad time right now as the editor for a group class project in one of my film classes, and every time I return to the sequence I want to delete the whole timeline. This is my first big film project I've been a part of where I had to work with a larger group and had to surrender some degree of control to other people. I love editing and was super excited to be the editor on this short film, but the script absolutely sucks and the crew prioritized cool shots over necessary ones (like full coverage).

Now when editing, I have a variety of missing shots, almost no b-roll, and just bad dialogue to carry the whole film. I have sequenced this project so many times, but every time I show it to the producer (who is also the script writer), he comes back with 20 critiques almost all consisting of things that needed to be done on set and I can't fix, and some bs on how deleting these two frames will magically make the whole thing flow together. And now he has rushed my deadline to having the whole film be finished by tomorrow for everyone to see, and when it comes out bad, he is going to say it is my fault for not taking his impossible advice, instead of admitting that his script was fundamentally flawed. I think he's blaming me because I'm the only one who still has the power to change the film now that shooting has wrapped, and his inability to admit his script is bad is causing him to lash out at me.

I just need some motivation and advice to get through this and produce something that can hopefully work. Has anyone else gone through something similar? I'd love to hear your stories if you have any. If you can't tell, my producer firmly believes this script is Sundance worthy and my poor execution is the only thing holding it back, even though everyone who sees it has said it doesn't make sense.