Marriage is a lifetime commitment. Sometimes loving your partner is not enough to pull the marriage through till the end, try talking to your partner, look at how you got to that low point and try to fix things back, but if everything fails then find peace elsewhere. Marriage vows says "until death" but you're not gonna want to just sit there and wish to die quicker so you can get out of the marriage.
Obviously marriage is a lifetime commitment. But at the same time, there is no point in staying together if the couple feel that they are not compatible to each other. Going through a lengthy legal battle will only deepen the wounds and worsen the financial situation for both the parties.