Skysblue, what struck me in your posts was that perhaps this "rupture" has came at an opportune time for you, it gives you the excuse to emotionally distance yourself from your therapist at a time when she was leaving for vacation. I wonder whether you've been subconsciously trying to detach from her anyway in order to cope with her vacation? Cancelling your appointment is perhaps you retreating to safety from the perceived abandonment of her forgetting something so important and the impending physical abandonment of her vacation but also there's maybe an element of "punishing" her for forgetting.

Could the strong reaction you are having be tapping into a past hurt where one of your caregivers made you feel like they'd forgotten you?

Realistically, i think you know your therapist had a momentary lapse in concentration, perhaps due to tiredness, to personal issues, to just too much on her mind. She hasn't abandoned you, she made a mistake, she's human and she's fell off that pedestal you had her on

She sounds like she cares for you and you for her and i think that's worth honouring, and giving her another chance. I think there could be valuable learning in this rupture.

I hope you feel better about it all soon x