heavy going

Also, heavy weather.

Difficult, as in Tom found calculus heavy going, or It's going to be heavy weather for us from here on. The first expression originally referred to a road or path that was hard to negotiate; the variant alludes to bad weather at sea. [Mid-1800s]

make heavy weather of. Make hard work or a fuss over something, especially unnecessarily. For example, They made heavy weather of the differences between their proposals, which actually seemed much alike. This use of weather likens a commotion to a storm. [Mid-1900s]