No one sees their marriage collapsing when they're standing at the altar on their wedding day, saying their vows.
The problem is, each partner's idea of "commitment" varies depending on their background and level of "stick-to-it-ness." For some, "forever" means until "til death do us part." For others it means "until the honeymoon is over."
Take your time. Do what you need to do to assure yourself you've done EVERYTHING you could to make it work. But at some point, it's time to move on. Only you can decide when that is.