Reddit mentions of Men's Stainless Steel Spinner Ring

Not to be a Depressing Danny, but I don't think this is the sub for this. I think you should try /r/lifeprotips, or search reddit for "habit breaking".

HOWEVER, I do have a tip that helped me finally stop biting my fingernails(I know it's not the same, but it's a similar habit in nature) after ~8 years of it:

• Get a spinner ring. (That's four separate links; the last two would be my first choices)
  
  I can't stress enough how helpful these are. They give you something to focus on, and they're just generally fun to have. Plus, not many people have them, so they're a good conversation starter. I've been asked by 50+ people about mine in the year or two I've had it.
  
  Best of luck.

I like to have something to fiddle with, too. I would look into either a tangle or get one of those rings where the outside spins like this