Before throwing in the towel, not that Schnarch talks specifically about where you are right now – Chapter 13 “Couples in the Crucible: Reaching Critical Mass.” According to him, couples experience the same detachment you describe. This is required as a critical mass state before true progress can be made in confronting the real issues. Up to this point confrontation of issues was avoided. You are at the fork in the road, this is the bottom, the worst that things can get. One direction takes you to divorce. The other takes you both to growth.
You have no more investment, and if your H is in the same position, then neither does he. There is no sense in playing any more games, making denials or power plays. You can be truthful and forthright with your husband now, tell him everything about yourself that he needs to hear and that you need to get off your chest. Doing so will not phase you. Hopefully he will feel the same way. If the two of you can do this, you will be on the upswing. Stick it out. Things can’t get much worse.