Not so much 'stress', but anxiety. Regardless how screwed up the old place was, you knew what it was and you were established in it. Changing to a new job with lots of unknowns can be a shock to the system. Even if it's likely to be very positive, it's the anticipation. Believe me, I have been in very stressful situations and been fine cause I had a pretty good idea of all the variables. And in most cases it's short term. Anxiety is different. Not always negative either. Just 'different'. This is going to change what you do and where you go every day. I had a really good phone interview yesterday, that will likely lead to another interview next week. The anxiety level is climbing. But I am not stressed.