Oh, boy! It is so scary when they run off. My son dashed across our Brooklyn street one day. Just standing next to me, and then zoom! Scared the life out of me and the (thankfully alert) driver coming down the block. I figured out my son was literally at "loose ends" during tantrums, and quiet talking with a firm embrace helped him calm himself. But that was him. Every kid is different. Hope you find your energy.
Thank you! It still amazes me how much of parenting is making sure your child doesn’t injure themselves! And so scary! Your situation sounds like it was far scarier than mine, but either way luckily the outcomes were both good. I admit that my anxiety gets the best of me, and so I become frustrated really easily, but I’m constantly working on it. I am still trying to figure out the best way to react to the monster’s outbursts, I think I will try your tactic next.