While this girl is over the top, and acting pretty insane- I think you need to consider, you lying about seeing girls, meeting up random new girls (even just for business), and going to another women to complain about your gal would no way help her get passed her insecurities. All these things probably validated them in her own way.. This being said, this isn't healthy. She is seeing a therapist? Good! Because this is way too over the top. She is fixating on it. And her going through your emails, will only make her more obsessed. You need to sit her down- if you still want to try- and explain how concerning all this is to you. Try to be as loving as possible.. This isn't just unhealthy for your guys relationship, but for her too. No matter how many reassuring messages she sees, she will never feel truly reassured. She will never feel happy and secure until she lets go of this behavior. She is holding on to her insecurities and fears. She is worrying what could happen instead of enjoying your guys moments now. Tell her, every second she is spending worrying and snooping through your messages- is seconds taken away from you guys and the moments you could be spending together.. I'm not saying you are in the wrong in any way- but if you want to know how to help her through these problems, take some of these steps. I've embarrassedly been the jealous girlfriend. No where to this extent- I've never even gotten close to going through my boyfriends phone. But feeling insecure and scared- even having bad realistic nightmares about it. I realized I need to just let go. To stop caring. Not about him, but about the future. I can tell you now, even once I would feel reassured, there was a part of me that felt even more scared. Almost like I was just waiting for it to happen, always dreading something bad happening. I finally gained more trust and let go. You gotta get her to do this. There really isn't much else. Don't show her shit- it will only further the problems she has.