I think a big part of this is that your therapist responded. It seems to me that you can trust that he will. That help and understanding will come, just not right at that moment.

Sometimes though it is hard to calm yourself once the swirling starts, but you can. I've noticed that repeated attempts to contact the therapist just makes things worse. Although it does give a "name" to the free floating anxiety. I am upset because....

It becomes an exercise in patience and tolerance. The more you practice those, the better you get at them, the more confident you become. It's a very positive cycle.

"I can handle it, it's not forever - this is tolerable".

Sometimes medications can help you to build that confidence. Seriously. It might not be the most popular opinion here, but anti-anxiety meds CAN calm the swirl and allow you to slowly develop the skills you need.

Just a thought.