I think this is a quote in Lundy Bancroft's book "Why does he do that" (not exact quote but paraphrased). This has been uber important to remember. The thing is emotional manipulation is effective. It's AWFUL to have to face that someone deceived / abused you showing they don't value you or care when you thought they did, and they spent all this time with you. That twisting of the stomach is something that doesn't come from love, it comes from manipulation. Love is warm and stable. Someone who makes you feel panic and anxiety didn't love you, or anyone, and that will destroy you inside. Remember though, it destroys you because it's abuse and manipulation, not because you aren't special, not because you lost something, and not because they are going to love someone else. They are a manipulator and manipulation feels twisty in the stomach and gut wrenching. You can't feel good about someone not having a soul but you have to insist, to literally save your life, and future, that you will not spend life caught in someones web who will feast on you. You can't live life pushed down or in a cage. This person can and probably will cage someone else up. It is impossible to win with someone who doesn't care, they can always manipulate a caring person. You have to leave though and just know that your injuries were caused by someone deliberately harming you for their own benefit. Grasp on to a better future for yourself with all you have so you have a hope for something better.
I am writing this over a year out of a relationship that was emotionally, psychologically and sexually abusive. The person was deceiving me from the time I met them about, well, everything. They had been sleeping with a woman over a year when I met them (I didn't know, they pretended they were celebate), and broke things off for a month (sleeping with her) and then came back and lied about the reason they broke it off for a month. Despite them saying they were alone, and not sleeping with anyone when we met and got to know each other I had overwhelming anxiety so I asked them straight on about sex and they fessed up. I was in total shock the whole relationship was a lie. The woman, according to them was someone they didn't find attractive, or smart, and didn't see a future with but they wanted to have sex with multiple people (Mr Celebate!). His story was he had told her he loved me and she blocked him during that month. I dumped him as he was a pathological liar to an extent I couldn't believe, and for 6 months without my answering any messages (or emails) he tried to get back in my life. This culminated with him showing up at my door with sushi and cake and I shut him down. ANYWAY I saw him out 6 months after him popping up at my door and he was out with the woman he had been with since before we met, still.
So, it was a reminder, as I did feel the gut punch feelings realizing he's had this girl around for probably 3-4 years that this is a hugely manipulative person and the only reason I have any bad feelings, and suffered so greatly, is due to this man's deceitfulness and manipulation. Thought the reminder and story might help others out there. One thing I am glad about - not believing a word he said about her being out of his life permanently. These people never cut off strings that give them sex and fight hard to keep everyone entangled in their mess. I feel like that woman is a piece of garbage, but I also am just glad that I am not the one willing to be with a guy knowing he sleeps with other people. No better way to tell someone they are better than you and you can't do better.
I wish she could be warned in a way she would believe!
Sounds like you were involved with a couple like the Hamolkas. Glad it didn't have such a tragic ending for you, though. That girl is the type of girl who'd trick young girls for her husband to abuse and even join in on the murder. Eventually, the man doesn't get as much of a kick out of having sex ans manipulation, so it escalates.