I think that you did awesome! While you still chose to eat it, you stopped and actually thought about what you were doing AND you ate sensibly the rest of the day AND you are heading out for a walk. You should be proud of yourself for doing those things, even though you ate something for comfort. The thought process there, which is helpful and you didn't allow yourself to let it get out of control, which is even better!
Sorry to hear about the overwhelming events, but it sounds like you know what you are doing and are being very mindful about keeping up with your healthy habits. Way to go!