Hi,
Have you ever had general anesthesia before? That, in itself, can cause depression. You have undergone major surgery and that is hard on you! All this different eating can be stressful and affect your mood. Lastly, if this isn't going as well as you hoped it would,UFOu may be feeling let down. If there was a big financial hit that your family took for you, bring on he guilt!
I am only on week 4, but was verrrry down for a couple of weeks. Do talk to your dr., tho. He/she may have some suggestions.