I'm so sorry about your loss. It's never easy to lose someone we love.
I just went through an incredibly stressful time as well. I basically quit eating for like three days. My weight never moves when I don't eat, so I was at a standstill.
For me, I had to just stick to eating when I could take it, and only eating bland foods because I didn't want to consume anything with any flavor.
At less stressful times, I tend to eat more. For that, I have to talk myself through it or try to distract myself. It's not easy when all i want is to feel better. I have to remind myself that eating will NOT make me feel good - I'll gain weight and that'll take longer to undo.
Maybe talk to a friend and just vent a little? Support can help.