Sorry to hear about your child and the loss of the precious stuffed animal. That can be draining.
At one point anything that happened only magnified how upset I was over the divorce process. When backing in to a parking spot, my fancy sports car dipped over the edge into a deep water filled hole where it was inexorably wedged. It was frustrating since I was in the cell phone waiting area of an airport and there to pick up my brother. I wailed to the AAA guy.. "My car is stuck AND my husband left me."
The same thing happened when I left the gas station with the nozzle still in the gas tank which snapped off making the car look like it'd grown a puppy dog tail. "I broke the hose AND my husband left me!"
My children would have difficulty in a situation and I'd feel inadequate. "They're hurt AND (/or because) my husband is divorcing me."
It added insult to injury. I came to realize that I used those and other times to focus on the unfairness, sense of victimization, emotional chaos of this painful process.
In the end it was the normal trials and travails of life where through my own frustration I assigned greater anxiety and emotion because of my own hurt.
Kids lose their favorite possessions, homework, get boo boos, sick. In my case I felt that sense of 'aloneness' so strongly, not having another parent, partner as backup.
When these things happen, it sucks but there's always a lesson. Keep your focus. You're a sweet dad. Take yourself for a walk instead of the black dog. Me.. I stumble, flail about then when something positive happens.. Hello! I'm back. The worst case scenario is never as bad as the reality.
Being strong doesn't mean meaning perfect. Try every day to be a little better in some way shape or form. The rest will follow.