There may be hundreds of things swimming around in your head that consciously, or sub-consciously clutter your mind, and make you feel anxious. It's important to release these at the end of the day. This is not a big deal like a daily journal, it's rather just letting your thoughts pour out; a decluttering of your brain.
So what, now what? Before you go to sleep, let it all out. Use the voice recorder on your smartphone. Talk (to your phone) in an unedited fashion, letting your stream-of-consciousness flow.