he cares for you. He probably waited til the last minute because he was hoping to be able to see you.
No doubt he could hear in your voice you were upset.
Our T sessions are cornerstones in our life-it's only natural to be disappointed when an app gets postponed. Try distract yourself, and believe that it really is less than 24 hours until you get to see him. And try talk about how you feel, and your reaction to the cancellation.