What do you do when your rainbows turn into dark clouds, when beauty turns to ugliness?

Life/people/ situations have a way of turning our attitudes from happy to sad, joyous, to angry and so on. When caught up in these moments what do you do to come back to a good attitude again. I've come to realize that we have to try to turn it around again to where it all began, In trying to keep our attitudes positive we must fight to stay positive. Example; Today when I wanted things to go a certain way that would be encouraging and inspiring to all involved, it didn't happen b/c the person I needed to make it happen wasn't available, or able to help make it happen. I was so disappointed it blew my bubble, and turned my good attitude sour. I reasoned within myself as I saw myself going down hill. Then I realize that I am control of my own destiny, and attitude. I have to learn to keep myself upbeat, and joyous. So I listened to a little song I love the rainbow connection from the muppet movie, and it seem to help me. We can't control others only can control us. I also realizes that I was letting my disappointment with that other person control my life for negative.