Does anyone have any advice?
look for another job?

nothing you have stated rises to the level of illegal.

Unless you have a contract that precludes you from being required to pack boxes, then your boss can require you to pack boxes. If you have a medical disability that would be covered by ADA, then you would have to request accommodations based on that.

Other than that, making the statement you are a senior level employee several times simply makes it sound like you believe you are too good to do menial tasks. Sorry but even the VP of the biggest company in the country can be made to clean the toilets if his contract doesn't preclude it and it is what his boss tells him to do.