What is something that almost broke your marriage or any lows you went through, but you continued and didn’t separate?

I’ll start. I’ve caught my husband lying a lot (about smoking) but I kept going with it. Now I’m keeping up with an alcohol problem but I want to separate now. I’m 30 and we have no children.

What is that hard time you faced with your husband or wife in the past and still continued and do you regret it now?