I'm not bipolar, but I do have similar reactions to most benzos and SSRIs.

Have you tried oxazepam? I've tried a lot of benzos over the years with little luck, but this one puts the pause button on my ruminating and lets me function a lot more normally for a few hours. It also helps boost my mood a little, too. I also don't find it as sedating as a lot of the others. Not even 30mg makes me groggy, really.

I know we're all different, but it's something that's really helped me.

Hopefully you find something that helps, I can relate to what you're going through and it's awful. Best of luck!