You could try speaking the words “Mind, be silent! Mind, be at peace!”
Have a fan on or something that produces white noise. Or use a website (even an app) called Noisli.
You could even try doing something called a body scan where you focus attention on your feet, then move up to your legs, etc. That, or focus your attention on some external stimuli. Anything to remove your focus from nagging thoughts.
I’d even suggest looking into meditation, but… Let’s not go crazy here. 
And just a reminder (totallynotachancetopushmytopic)