Andy wasn't an 'I told you so' kinda guy but he was tempted, a little, to say it here. He knew it was mean and mostly came from his worry and frustration at being powerless to help his friend. Andy just took Kurt in his arms for a moment, holding him tight, sushing him gently as he tried to calm him down.
He understood Kurt's pain, he knew what it was like to feel like everything was falling away. Unlike him, though, Kurt had not lost everything. Blaine was still there and still in love with him. It was fixable. There was a way back.
"Shhh, it's okay. It's okay buddy," he said, swaying gently. "It's okay. It's gonna be okay. He's still here. He hasn't left you. It's okay." Andy knew there wasn't much point using reason until Kurt was calm so he kept whispering assuring nothing until he was.