I think you answered your own question, you get those thoughts when you are TIRED, BORED, or ABOUT TO HAVE FUN. Lack of sleep is a major issue in my anxiety, and I see from here, alot of others too. Boredom speaks for itself! Don't be bored anymore! Find something you love! Then do it! And as for about to have fun, like me, maybe you feel inside you don't deserve to have fun. But you know what? You do~! You most definitely do deserve to have fun and enjoy yourself, you are very worth that. Blow off those thoughts.....you are not any of them....and in the end think "are they true?" "No, they are just negative thoughts" Then go out and enjoy life.
JCR