It typically was because people kept posting their youtube or stream spam. I never 100% understood it either because what if it was an actual relavant video, then why not allow it?

I remember trying a home made cardboard one that worked pretty well. Make it just big enough for him to stop messing with it.

I found this link with some suggestions while trying to find a picture or video https://pangovet.com/pet-lifestyle/cats/diy-cat-cone-collars/ they make a paper plate one which is the same idea. Might be a good place for inspiration.

Finding a better therapist would help. Also finding the right people to vent to. Some people handle it better than others. You can try even saying, “hey, I’m not looking for advice, I just need to vent, would you mind being an ear?” at least that way you have their permission and they understand that they aren’t expected to fix whatever the issue is. Controlling who you vent to is also a good way to prevent venting to the wrong asshole who can’t shut their mouth.

I know you said no Journaling, but also consider a journal app on your phone or even just a Google docs. It’s a discreet way to vent briefly. I remember also taking a pen and a notebook and writing how I felt over the same line over and over so it wasn’t legible to anybody walking by. It’s likely something you’ll never read again and it’s about letting out the frustration more than anything.