Gale was cradling you against his chest, pushing aside his own fears. You kept telling him over and over and over that it wasn't your fault, you hadn't killed the innocent Bard wishing to join your team. He wasn't entirely convinced, but you're his lover... his everything. So why would you have woken up with blood on your hands?
"Darling I believe you," he assured you, though he was secretly thinking of spells to use in case you felt the urge to kill again.
The way you described everything to him, memory loss, horrible thoughts, it sounded like the 'dark urge' he'd read about earlier in his life.
"You're alright, everything is going to be alright sweetheart," Gale wasn't as convinced as he was trying to come across, but he needs you to keep calm and believe him. He would figure out how to stop all of this later, for now he just needed to stop you from scrubbing your hands raw.