I hate to tell you this, but only you can truly answer your question. Only you know how much you've gone overboard, and how the pregnancy affected you. Be honest with yourself. I'd hazzard a guess that to be this stressed over it, you know
how badly you ate. Does it really matter how much weight came from what? You're still going to feel bad for falling off the wagon, even if a lot of the 10lbs is
from fluid retention. But give yourself a break, it happens to everyone, and I think you have a much better reason than most.
Here's the question: even if it is all your fault, are you really going to quit? Are you really going to say, "So I went through this horrible event in my life and gained some weight. Might as well give up entirely." Of course not!
Give it another week or so. You're still dealing with it. You'll probably feel a lot better here shortly.