Some context: I met my advisor during my undergraduate studies (I am pursuing a PhD at the same institution). I took several upper-level elective courses with this professor, and received top grades in both. Both courses were related to field A, in which I have a strong background. I decided to do my PhD at this institution due to positive interactions with this professor, alongside some other personal reasons discouraging relocation. This professor is the only one working in field A at the school.
I contacted this professor expressing interest in working together approximately 5 months before the start of the PhD program (the previous spring, soon after I was accepted to the program). He very enthusiastically accepted my application, and immediately asked me to begin working on a publication in field A with applications in field B, independent from his group's previous work, with a deadline in the next month. I scrambled to put a paper together on my own, which was ultimately rejected (I believe rightly) on the grounds of being insufficiently developed. I also did some work for this professor for a large grant proposal, which was accepted. This all happened in the summer before I began the graduate program proper.
Over the next semester, I focused on developing the work done over the summer. I was also brought into the fold about the grant project (I was not given all of the details when I contributed). This project has far more of a focus on field B, with a tenuous connection to field A. I changed the focus of my work to "strengthening" this connection, and reading textbooks related to field B for the purpose of properly integrating field A. I was told to prepare a paper for a conference entirely dedicated to field B, to demonstrate the applicability of the work. This paper would contain a high-level overview of the the field A material for a field B audience.
Fast forward another semester, and work on the paper mentioned prior has continued (I am contributing all of the material; my advisor is a coauthor). I believed work was going nicely: I was expanding upon the previously rejected paper, and personally learning a lot about both field B and field A by working through textbooks. However, I do not believe my knowledge of field B is at all sufficient (I am unable to read and understand current research; field B would fall under an entirely different undergraduate major than field A).
Right up until the paper deadline, my advisor seemed fine with all of this. I have been presenting drafts weekly for several months, and he has given me minor suggestions, helped fix phrasing, etc. However, about one week before the conference deadline he absolutely exploded at me on a teleconference, partially in front of another professor. I was told that the paper was "garbage" and that nobody in field B would understand or care about it. He implied that I had been doing nothing for the past year, despite my weekly progress reports. Further, I was told that this paper would "make or break" our grant funding, and that in its current state would likely cause all of us to lose funding. I have been told to rewrite the paper, focusing only on field B and disregarding field A entirely.
I am extremely distressed. Until today, our relationship was nothing but cordial and I thought I was having a great first year. Now, I feel humiliated and defeated. I am being asked to write a paper in one week in a field where I am completely unqualified. I am told that the quality of this paper will determine not only my future funding, but the funding of two professors as well. I love and am very passionate about field A even still, but this experience is making me despise field B, which is not helping my outlook or mood. In one day my academic life (and by extension personal life, since I spend almost all of my free time reading textbooks) has gone from being something that brings me joy and satisfaction to something very uncomfortable
What would you recommend I do in this situation? I certainly do not wish to publish subpar work (and any work I do in field B will very likely be entirely subpar). Is this just how graduate school is? I believed my advisor accepted me due to confidence in my abilities and a shared research interest; now I worry it was for other reasons (my GPA and GRE scores are much higher than the average for the school). I don't know what to do and I feel frustrated and alone.