Hi Janet, I went through something similar after my husband went into remission from non-Hodgkin's lymphoma. I just couldn't get past what had happened. I saw a psychologist too, and it was really helpful. (I was incidently diagnosed with a lifelong anxiety disorder as well.) One of the strategies I learned, which helped me the most, was to practice mindfulness. This means concentrating on what is happening right now- what can you see, hear, smell, taste and touch? This is especially good during times of acute anxiety, as anxiety is usually based in some mythical(terrible) future. Another good trick I found (by accident!) when my emotions are spiralling out of control, is to write with my non-dominant hand- it's basically an easy way to become mindful, because you really have to concentrate! Write whatever you like- your name, the alphabet, a shopping list, copy out a paragraph from a book-anything will get your mind off your thoughts, and onto the movements of your hand on the page.
I hope this helps a bit. Please let me know how you go. love and hugs, Emily