Sorry to hear about your loss, you have to try to think positive.. I know that my seem hard but if there is one thing with stress it can actually make you gain weight because you give off this chemical.. can't remember what it is called but it works against you. Try not to cheat .. do something else, go for a walk, ride a bike, call a friend.
You do not want to gain back what you lost as this would just put you in a deeper spiral.
We are here for you!!
Take care and all the best!