Does anyone have any tips on dealing with this bullshit? Why the fuck am I jealous about shit that happened before I even met my girl.

Was going through an episode and decided to go through her phone. I already know im not going to find anything that shes currently doing wrong but my brain told me to go read her old messages to find out if she “really” loves me. 

This is not the first time ive had jealousy for her previous partners. Most of the time ive been able to show myself that it doesnt make sense and make it go away. But this time is a little different. The messages I saw really triggered me since the things she was saying to other guys was the same kinda shit she would say to me. “Oh you are so this” “ive never met so eone with this” “you are so this, i cant believe”.  Like word for word thing shes said to me and I believed made me special in her eyes. 

Anyways enough fucking crying, any fucking advice on how to work on this and get over it?