(deep) in the weeds

1. Of a restaurant worker, completely overwhelmed with diners' orders and unable to keep up with the pace. I was all alone waiting tables during Sunday brunch, so I got in the weeds almost immediately. Even with a full staff, Friday was so busy that we were deep in the weeds for most of the night. I spent my whole shift deep in the weeds, so no, you couldn't pay me to stick around here for another hour. See ya!

2. Overwhelmed with problems, troubles, or difficulties. We were starting to get deep in the weeds on the lead up to the software's unveiling, but we managed to make up some lost ground in the last couple of weeks. My relationship with Joanna has been in the weeds lately. Boy, we're deep in the weeds now. I'm worried we're going to have to scrap the whole thing.

3. Totally immersed in or preoccupied with the details or complexities (of something). I'd like to come out tonight, but I'm deep in the weeds with my thesis. When I left them at the library, they were deep in the weeds analyzing Mrs. Dalloway for their presentation. I think you're too deep in the weeds to see a solution. Some time away from the project might help.