Not one therapist? Wow, amazing. Maybe it doesn't matter how or why, but perhaps what matters now is this is what you've got, and this is what the marriage is. It's been a number of years, and you now know fully what you've got. And it can come down to choosing a life of happiness, inner peace and fulfillment of one's desires in life, or not, and my guess is you'd choose happiness & fulfillment over misery, pain and anguish... as would I.