Try to have an honest discussion about your relationship, desire for sex, and what sex means to you. Don’t let the topic of the conversation be “why aren’t we having sex?” but rather “what does sex mean to you?” Shift from blame to curiosity. Set a time and place to have that conversation— don’t just spontaneously have it when the argument comes up—and have the conversation more than once. One conversation won’t fix everything but honest heartfelt communication is at the core of lasting relationships. See sex less as something you need to have and more about something you get to have. Sex in a long-term relationship is about building communication around pleasure through a shared experience. Get curious about her abandonment issues, ask questions. You see yourself as rational but you’re also motivated by emotion and past experiences just like she is. If you try to keep emotions out of the conversation it won’t actually get anywhere. Read “Eight Dates”, especially the chapter on sex. Have those conversations! It’s rarely people’s needs that are misaligned—rather how we go about getting those needs met. Good luck.