My contribution to this thread isn't so much advice that's been passed on to me, more a book in the same vein.
I'm a worrier, I care what people think about me, I worry about what's going to happen tomorrow, I mither about nonsensical things that I have no control over.
My daughter is always telling me that a lot of what I worry about is wasted energy but she was trying to get blood out of a stone so she bought me a book.
I apologise before I go any further for the title of the book (just as my daughter did), I'm not a person who swears and I could have taken exception to it but, after reading it, the title is very appropriate. I'm hoping that I don't break forum rules by posting it. It's "f**k it", written by John C Parkin. I don't necessarily say the word printed in the book but I don't break any rules by thinking it. 