How can i help this struggle in relationship?

He's staying up all night? Sleeping on the couch? Is it possible he's getting heavily involved in a addiction? That was the first thing that popped into my head....it's a hallmark sign. No, you don't have to allow this to happen over and over. Only you can decide when you've had enough or when it is no longer able to be mended. I hate to say it, but maybe stay up some night and see what it is that he does until the wee hours of the morning. Hope things work out for you.