Try this: handwrite your negative thoughts out. Then try to prove to yourself why the feeling isn't true. Again, write that out. Now tear up the paper and get rid of it. Don't keep a journal of it.

You would be stunned how much this helps. I got this technique from a doctor who wrote a book about living with what he calls neuropathic disorder (in my case chronic pain). In the book he describes how we can easily make ourhealth worse through negative thoughts. It's very possible for bad feelings to cause physical pain because the two share the same neural pathways, so it's critically important not to let your emotions get the better of you.

The book is called Back In Control (the author is a back surgeon). It's a good read for anyone with chronic illnesses, or even just for those who want to explore how to better control their emotions and live healthier.