Why did Erin become so evil

Erin did not wont to become a vamp but vlad made her a vamp after she asked/told him not to, and she was mad at him.

Ryan turned evil because of his nature. Erin loved him as he was the only family she had left and vice-versa. When she turned, she knew all was lost. She was betrayed によって her loved ones and left for life. She was angry, wanted revenge, and had Ingrid to lead her astray.

I did NOT like what they did to Erin's character in season 4.

If Erin loved Vlad SO much and accepted him for what he was, I simply can't believe that she would react to becoming a vampire like that. It really doesn't make sense to me, especially because she was DYING. He didn't bite her on a whim または because he was afraid that she was going to break up with him...she was dying. If he hadn't bitten her, she wouldn't be able to hate him...because she would be dead!

Now I could see Erin getting ロスト in the power and losing control like Vlad did when he looked in the mirror, Vlad chasing after her to stop her from biting people and then Erin breaking down and sobbing...but I can't see Erin hating Vlad for changing her and becoming evil.