Toughness is good and bad. When it is prioritized over other qualities, it is bad. When it seen as a reservoir to get through tough times, it is good. Regardless of your situation, if you want to improve your mental toughness, here are some books you might want to consider: The 5 Best Books for Increasing Your Mental Toughness | Inc.com
Be as tough as you need to be, not just tough for toughness sake.