I'm sorry you guys are in so much pain. It must be awful. But I do not see why you would think that a divorce would help. Marriage vows say "for better or worse, sickness and health" yadda, yadda....
What does getting divorced look like in your mind? Do you imagine it to be a magic cure for your unhappiness?
I hope you guys can work through this because I seriously doubt that divorce will bring the relief you seek.
And it's devastating to children. Even adult children. I don't know why so many people lie to themselves about this particular fact either.
Hang in there. We have some great posters here who can help.