I don't know what the right thing for you to do is but you should try to imagine what your life could be like if you were able to somehow reconcile with her and really have a genuine marital relationship as well as imagining what it may be like if you divorced.
Remember, the "truth" comes first, always. She knows you will never live through Armageddon so I believe she is limiting her exposure to pain and hurt by pulling away from your relationship. The witholding of sex is a way for her to make you see sense (her version) and return to J; it's the next thing in the arsenal since she realistically can't shun you as she would someone else.
My marriage has ups and downs, right now it's down. So my advice may be a reflection of my mood.