She had a previous relationship where she has told me whe was very angry because he didn't love her and strung her along.
Most Helpful Guy
She dumped you because she got nothing from you - she didn't see you emotionally invested, she didn't see you care about her, she is one of those girls who needs obvious drama in her life that she can SEE, because you're just a black box to her. She has no clue what is going on inside you, and she fills that silence with all the worst things her self-doubt can invent.
When she said she wanted to break up with you, she was saying that to get a reaction from you. She wanted you to emotionally explode, tell her that you didn't WANT to break up, and how much she meant to you. Instead you went "Okay, whatever you want"
You were not doing her a favour by giving her what she said she wanted. You were frustrating the hell out of her because she didn't get the emotional reaction from you that she needed.
A girl like her doesn't want you to give her everything she wants on a whim - that's not important to her, and isn't what she actually wants. She wanted closeness with you, understanding you, communication with you.. but mostly she wanted to know how you felt and thought about things.