Really bad sense of doom

I have panic disorder. But I also have bipolar and PMDD.

Last night I've just had awful sense of doom. Lasted about 3 and a half hours. I called my PCP after hours. He said that since I just had a really thorough cardiology and neurology workout he is not concerned that I have something dangerous going on and he's sent over some lorazepam that I just got the alert to go pick up. He also gave me an appointment tomorrow.

After speaking to him last night I managed to calm down a little bit and I did manage to get some good sleep about 8 hours. I woke up felt okay but then the feeling came back. I've been like this for a few hours. I'm shaking and crying.

Any words or advice? I'm trying not to go the ER