Sorin was patient and would wait all day and all night, however long it took for Sidro to be comforted and gather himself back together. Consequently, being able to focus his own thoughts to avoid negative emotions that would bleed over to Sidro, Sorin's ability to focus with his magic was strong as well. He was not as behind as he thought he was in his magic lessons because he had already learned a very hard lesson: how to be still.
The length of time it took Sidro to settle was alarming to Sorin, but he continued to send warm and loving thoughts. He'd talk to Sidro later about why he had waited so long to call, right after he apologized for not being there without needing to be asked, and neither of those would happen before Sidro was himself again.
When he felt the boy's shaking stop and heard his breath grow steady again, Sorin looked down at Sidro and smiled softly. "Better, but drink this." Not letting go of Sidro's hand or drawing away, Sorin reached back with his free hand to pick up the thermos and open the spout. "I made it. Careful. It's hot."
Sorin could feel how weak Sidro was, no doubt from exhaustion, and so he helped his blood brother to sit up enough to take a sip. Sorin leaned closer and kissed Sidro's temple.