What does this mean - yes she was drunk, but underneath that?

There is nothing good that is going to happen with you and this woman. I think you're used when her marriage is having a rough patch and she needs that extra attention in order to feel good about herself again. I think the only person suffering in any of this is you, and if you love yourself, you will move on to a woman that is available. This just isn't meant to be, and you're enabling her to use and hurt you. You're better than that, move on. It isn't love, it is unhealthy obsession with what could have been.