I spend more time updating my Kanban boards than working on my projects

I recently went on a training course on Agile project management, and I decided to start using a Kanban board to manage my day-to-day work. My aim was to streamline the process of managing all my to-do lists and keeping my boss up to date on my projects. However, my Kanban board is out of control. I have post-its on top of post-its, and I spend so long trying to sort through the information and keep everything neat that I am actually spending less time overall on my work. What am I doing wrong?