I think PDM gave a pretty extensive breakdown of what you need to ask yourself. But 3 witnesses are better than 1 I suppose.
First off, it's difficult. There's no decisive answer, and no one can tell anyone what is best. Every situation in everyone's lives is different. No one knows truly what 2 people are going through. With that being said, objective perspective help you, but I think they help you to understand and see what is really going on inside of you.
Second, if there is any doubt, I think it should be worked through. For one, you made a promise. I'm one who believes in standing by my word, it shows integrity. If you haven't got the words you speak, you have nothing. Promises shouldn't be broken unless all possibilities have been exhausted. Secondly, there's a lot at stake. Divorce is difficult, a lot of people get hurt in the process including yourself.
Now. How do you know when to get out of it? I think you'll know. A counselor can help see what's deep down, to realize what's there. A counselor can also help with the guilt that will definitely follow, the regrets that will be there no matter how easy, smooth, and mutual the split was.
If there's children though... I'd say that makes things different. I can't give opinion to that because I haven't spawned yet.
I will say though, that there was a period with me and my husband where we pushed every button we had. Purposefully and spitefully. No lie, this went on for a year straight. It was terrible. There was resentment, hatred, anger, and very bad words exchanged. Things were dug up that shouldn't have been, and there was a lot of pain.
It took us breaking up for me to realize that what we were doing was wrong. That we really loved each other, we were just going through a trial battle of the wills. We only stayed apart for a week! Neither of us could take it. We've been happy ever since. But I don't think we'd have been there if we didn't split first, and take a step back.
With that said... maybe a split before a definite divorce is best?
