Pastrychef, is your husband currently in any therapy? He does sound rather stressed (as do you). The salad dressing does seem like a minor issue, however please read the following article regarding stress and PTSD sufferers:

Understanding PTSD - Edited

It is an excellent article and I personally found it most helpful in my understanding of PTSD. Sometimes a seemingly minor issue can be the limit for them, as you will see after reading the article. I apologize that I have nothing more to say tonight as it is late and I must sign out, however do take care.