That really is an awful feeling that always makes me feel trapped in a way... I can completely relate. Can you take a run somewhere? Or even take a walk. This is going to sound dumb too but I've been known to write a journal entry on my phone while I pace in my house. I'll write literally everything that goes through my head.

Something that I do also sometimes is if I'm laying down to go to sleep I'll just let my brain talk itself to sleep. Instead of thinking "ok, shut up thoughts, it's sleepy time now... shhhh" I just let the voices talk. Sure... it gets loud... but it's a nice distraction really. You just kind of work WITH that thing... whatever it is... that has taken over.

Even if this only results in a few hours of sleep it always makes me feel better at least.