Gwen was in a war, a war with herself. No matter how hard she fought, she could never win. Ever since she came out of the tower, she was a completely new person. It was as if someone was controlling her, and she knew exactly who that person was: Morgana.
Morgana was always there when she was being tormented by fear and agony. She was always there to calm her down. She was always there to tell her that she was going to make it through. She was always there to push her through her stress.
No, she thought. She was the one who got me here in the first place.
As much as Gwen wanted to push Morgana out of her mind, her body was already corrupted by Morgana's powerful words. No matter how hard Gwen struggled to regain control of her body, she was only pushed down and was forced to watch others get hurt because of her.
Morgana had imprisoned Gwen in her own body, and there was nothing Gwen could do.