I think assuming your therapist is being mean is only contributing to your desperation.

I understand that you have abandonment issues. But I guess I don't understand how you can forget the wonderful pumpkin celebration that you just had with your therapist. Or the lovely session that you had with her previously.

Just because your therapist doesn't work on Fridays does not mean that she doesn't have other things to do that are majorly important to her. She will get back to you--I know she will! Just hold on and try to reflect on the good times you've just had with her. That's what memories are for--to save you from moments like this.