Curt,
What have you done in the past to make it through these episodes, what has helped you?
Have you worked through your issues with a therapist? I see your work pattern as absolutely grueling and I wonder if this is not triggering your anxiety. You are not getting enough rest, you are away from your family and I would venture to guess your nutrition is not the best right now.
Cognitive Therapy is a very effective way of understanding how you think, and therefore feel. Cognitive Therapy helps us to explore our underlying belief patterns that result in negative, irrational and unhealthy thoughts. It then allows us to explore our thoughts and replace them with more useful ones in order to manage our emotions more effectively.Take a look at this site and consider working through it at your own pace. It is free and you can do this right from your computer.
MoodGYM http://moodgym.anu.edu.au/
You have my support.
Kitt