I took a Jocko (he's a famous navy seal) quote and made it my mantra, it's similar.

He said "Be tougher."

To paraphrase the context: mental toughness is a choice, and if you aren't as tough as you want, you just have to be tougher. Choose it. In each moment when you are tested.

Thanks for your comment. For a while I had been wondering why I couldn't focus, wasn't able to accomplish some simple long term goals, etc. Be tougher was my fix, and your comment expands on some ideas in a way that makes sense to me.