Hi and welcome.
I agree, it looks like your only option (that would be covered) is to go to the ER...though they are unlikely to send you home with any medication...
You may have to tough it out through the weekend...make an appointment on Monday, and pay out of pocket. Just find a doctor that can see you ASAP...even if you don't end up staying on with them...you can at least get a prescript
ion so you don't suffer discontinuation effects.
Here is a site that may help with other ideas to reduce withdrawal issues. www.theroadback.org/
Use your coping skills to help reduce your anxiety as much as possible.