rekt

That’s what I give to my oldest dog. He seems less anxious now.

Something startled it most likely.

We have electric fences here on the farm. One dog used to go under the wire untill it got a good zap. Now it's scared and displays signs of anxiety more often. The other dog is also but because he got zapped so many times doesn't care as much.
I would never castrate them as it only messes up the wiring in the brain.

You just need to get their mind off and build the confidence back up. Spend a day out in nature, take them to a beach or a long walk in a park. Staffy commonly suffers from separation anxiety. I would take it to the barn and let it terrorise the rats for an hour they are good at it.