I would see if I could figure out discreet problems and then come up with some ideas how to solve or cope with them better. Just talking about "stress" can be more stressful? Figure out the top three things on your job, exactly what at the moment about your son's illness that is hard for you, etc. I like to read books like the Heath brothers' Decisive: How to Make Better Choices in Life and Work: Chip Heath, Dan Heath and get ideas on how to cope better when I am feeling overwhelmed.