There's a message on my therapists phone, says if you are experiencing a life threatening situation please hang up, dial 911 or go to your nearest emergency room.

Facts of your situation, at 2am from your email address, an email was sent to your therapist. Of which, your therapist emailed a thank you. Then, you emailed and therapist wrote, she would attempt to contact you yesterday, which you sat by the phone(in theory) all day, and she didn't call.

This, is a holiday weekend, and most people I know are out of town, hosting out of town company or spending a great deal of time with family.

Of course, it is important, for others, to make attempts to do what they say that they will. At the same time, humans are humans, and life gets in the way, especially, this time of the year. Perhaps, this isn't a reflection on the importance you are to your therapist, as a client? Just a reflection, on this being a big travel/family weekend.

You wanted to discuss, an email that was sent to your therapist, from your email account, that you don't remember sending.

SI sounds like it could be life threatening. It doesn't sound like, even my own therapist handles life threatening emergencies, when he doesn't directly answer his phone.