The way I see it, and the reason that I'm so adamant that people should not divorce, is that the Bible never really discerns between mental, physical, or emotional abuse, and so they are difficult to define. Yes, physical abuse is pretty clear-cut and it would be wrong to say that a woman should stay with a man who physically abuses her.
The danger of mental or emotional abuse is that someone can claim they are being abused in that way for practically anything (like "he makes me do all the housework...it's emotional abuse") and twist it in their own way so that others agree with them. It gets to the point where people will just start saying that they aren't "in love" anymore, and the other person annoys them, so staying with them would be mental abuse. In that case it's just like dating; you get sick of the person, then you leave. There is no incentive to work things out. I think this emotional/mental abuse thing, in most cases, is just an out for people who didn't value the sanctity of marriage in the first place and want to leave their spouse and justify it to themselves and/or the church. It is also done with the mindset that they'd be better off with someone else, i.e. getting remarried, which the Bible says makes you an adulterer.
I'm not saying mental/emotional abuse isn't a thing...I'm simply stating how dangerous that notion can be.
If there are problems in your marriage, yes, you should absolutely tough it out.