You'd gotten changed by Cazador. It was your first time, and Astarion was there to help you through the change. He currently had you pinned down, giving a chuckle.

"Calm down darling, I'm here. I know you're hungry, but you have to control your urges."

He was trying to mentor you, to help you control yourself. He knew firsthand how difficult it was to be alone during your change. He wouldn't let you go through that hell, not alone.