Divorce doesn’t harm the family only when children are young. Marriage is a bond that forms a foundation for family networks. This nonsense about “unfulfilling marriage” is simply our hyperindividualism on shameless display. That’s not the job of your marriage, to offer you some kind of fantasy “fulfillment”. Your dissatisfaction is likely rooted in your self-centeredness. We know that selfish, self-centered, self-obsessed people are the most unhappy people. Well, here’s a thought: stop prioritizing your “happiness” and your “fulfillment” and be an adult. Recognize that your marriage is for the good of others. A large part of being an adult is to enable the common good of your family and your society. Your family depends on you. Your society depends on you. Divorce motivated by abuse is one thing, but “lack of fulfillment” is a sign of perpetual adolescence.
Want to be happy? Happiness is found in virtue. Learn to live for others and stop being a parasite who burdens his spouse with the impossible task of making you “happy”.