2) Get in the habit of writing down everything that's in your head. I keep a simple bullet journal so that everything in my head has a single place to go. Note: It's better to actually physically WRITE it than to type it.

3) Hobbies. Find something your passionate about that you look forward to doing when you're off work. That'll keep your brain off of the other stuff.

4) Exercise. A lot of time, mental anxiety can be cured with physical effort.

Those are ways I've successfully done it. Any of them work for me, but they're ordered here by the most effective (for me).

Just find a way to get it out of your head, and it should stay out until you get bored.