(18M)(18F) I’ve been in a relationship for 2 months, but is already questionable

So I’ve been in a relationship with a girl from my class for 2 months. I moved to a new school and when we seen each other for the first time, we started liking each other. Month and a half later we claimed our feelings and started dating. Everything was fine the first few days, but then till’ this day she’s being toxic. She’s jealous to every girl I know, argues with me for every mistake I make, even wanted a breakup 2 times. I never knew what the problem was, I thought that’s her way to show her love to me. But then after some talks with mutual friends I found out that it’s her ex’s fault. So she had one ex, that was her first love and she loved him. He even cheated, but she forgave him, but he was jealous too, didn’t let her have boys in the friendship circle and even beat her many times. She cheated on him too. I was mad when I found out, because basically she thinks I’m just like him. She barely forgave that I didn’t want to show her my chats (I just want my private space to stay private), what about a cheat (by this i mean, that she loved him more than she loved me)? I think that she needs time, but this may take years. I’ve had girlfriends before, but I’m feeling that she’s special and would wait, but I think if she decides to breakup with me, she won’t come back this time.

TL;DR My girlfriend thinks I’m like her ex, who controlled her beated her and cheated on her, so she’s controlling me now, wanted a breakup 2 times and i’m not sure what to do