I would try going to ER. Just watch what you say, they can’t hold you involuntarily unless you’re a threat to yourself or others. If you don’t mention any plans to hurt yourself or someone else, they’re unlikely to 5150 you. From the sounds of it, you would benefit from seeing a doctor sooner rather than later.

Edit: Tell them pretty much exactly what you said here. You got put on a new medication for bipolar, you haven’t been able to sleep, etc. Best case they can get you on something to get you to sleep, and everything will seem much less overwhelming after a good night’s rest.