One of the best ways to go from upset to feeling good is shifting your focus to what you are grateful for. It is very difficult to feel stressed and grateful at the same time!
To help me with this I use an application where I every day can fill out things I am grateful for. You can also upload a picture and write in a journal. When you get into the habit of doing this daily it really makes you feel good. After a while you have long lists that you can look at that will put a smile on your face.
If you have an iphone you can use this link: grattitude journal