Hi Philly,
I totally understand. In fact, I was going through the same thing today! My job has been terribly stressful lately and it is extremely important to me that I do well, etc., just like you. I also have suffered through a major depressive episode and when I experience this kind of stress and have a reaction of tears to something I normally would take in stride, it makes me very nervous too. It's a good indicator to me that I have to keep a close eye on my symptoms, reactions and such to make sure that I stay within the acceptable range. It means I have to take better care of myself, although have never been particularly good at that! I NEVER want to dip down so low again if I can at all avoid it. It was, unequivocally the worst time in my life.

So, long story short, you are not alone my friend! I hope tomorrow is better for you!
Okie