I am so sorry for your pain and for your doubt. It is a natural thing to come on the heels of such actions.
However. As much as I hate to say this against my gender... it is a female ploy. She may, in fact, leave you. I won't say that isn't so. But I see this as more a female 'test,' a huge hissy fit, than anything else.
Stick to your guns. You don't have to be mean, or cruel, or pissed off. She MUST understand that this is an issue on which you will NOT budge. She is going to rebel, resist, test, etc. It will come in many forms. I would not be surprised to hear you reporting a crying jag within a few days.
BE CONSISTENT in your unwavering boundary on this issue. Do it with quiet strength. Do not blame. Do not turn it back on her or her issues. Stay steadfast in... "I'm so sorry you feel this way. I understand. I do. I understand how you think it is all about sex. A trade-off. I get that. But to me, it isn't. This issue, and how WE deal with it, together, is central to my concern on moving forward with you."
See? It isn't so much about sex OR unconditional love... but about respect and how the two of you, when you reach an impasse, will deal with problem-solving. It doesn't matter WHAT the issue is... but if you respect one another enough to tackle the issue together, or not, and pull a power play (a.k.a. hissy fit).
It hurts for you both now... but what comes of this will determine how things will go for you in a marriage. Be strong, be consistent, be empathetic. Try not to pull punches on her and get into a pissing match. Do not apologize for what is important for you... but don't shove it in her face, either. That will give her room to throw her hissy fit... and then step up to the plate, if she has it in her.
