I had similar frustrations with google analytics and decided to do the same.
Are there best practices to follow? I just have a table with: id, id of thing being accessed, user email, time, event enum, and notes.
It works well enough, and I have a python script to query the table and aggregate and print graph or print the results. But it would be great if there was some "bring your own data" dashboard that would let me view the time series w/ things like filters