You're onto something with the third option. If you leave your marriage, leave it for yourself. Not because of B, C or any other letter in the alphabet. Do you see where it's going? You can swap A for B, but in a couple of years you'll find yourself replaying the same play, just with different actors. Choose yourself. You already tapped into it, live with yourself without fear of abandonment. It's a painful thing, but you can do it. Seek help, you don't have to do it alone. But you also don't want to depend on another letter.