For my birthday a couple of years ago, knowing that I'd been battling with anxiety and depression, a very good friend gave me a little book called "50 Things to Always Remember...and One Thing to Never Forget" by Douglas Pagels. The blurb on the back says, " Words to Live By and Wishes to Share With Someone Very Important". The following quote is my favourite.
"Nothing wastes more energy than worrying. The longer one carries a problem, the heavier it gets. Don't take things too seriously. Live a life of serenity, not a life of regrets. Make your tomorrows everything you want them to be. If there is a change to be made, set the stage for tomorrow to bring it. When you're not sure what to do, trust your intuition and just wing it."