Hi TOH, best not to look too far into the future because non of us know what that will hold.
Just ask yourself one question IF it all comes to nothing with B will you still be happy with D your H ? Maybe happy is not the right word, will you still think deep in your heart that you did the only thing you could do at this stage in your marriage? I do wish you well and all the happiness in the world. Life is indeed short and I say grab it while you can but know that even alone you will still be just fine.
