Expenses Chart W/ Chart JS

Tried to code it with pure JS without external libraries. Proved to be more difficult than anticipated. Was on it for about five hours and gave up and used Chart JS. I didn't want to use an external library, but did anyway. What should be the approach in using external libraries? Should they be used or not? I personally found it a lot easier to create the graph with the json file using Chart JS. Should I have used it or not, any help is appreciated.

P.S. I AM STILL NOT INSANE!