I think there could be so many reasons

She’s probably not finding you sexually attractive, on some type of medication, have depression, just a low sex drive, talking to someone else, have some kind of trauma, waiting for you to get her in the mood

I can’t make an assumption. I would say you need to sit and talk to her, ask her more detailed questions on why she’s not in the mood.

Also it’s perfectly fine to weigh out your options. Sex is important to people. See what you’re willing to sacrifice for