As many have said - there is such a broad range of workable relationships. It is important to remember that when children are in the picture, the decisions taken can have such a big impact (I say, as a child of divorce...which happened when we were teens). As parents, we all want the best for the kids. Having said that, though, both parents need to be happy to be good parents.
It's true, as some have said, that different people have varying needs vis a vis sex and intimacy. I have, at different times in my 25 year marriage, maintained separate bedrooms - once, when the kids were tiny as my husband had really full-on work that, due to different time zone coverage, sometimes had him on-line in the middle of the night. Other friends were aghast and thought we were destined for divorce if not sharing a bed. Definitely not the case. In fact, the friend who first said we'd be split up soon did, in fact, get divorced 10+ years ago (so, maybe he was no expert)!
Now, my husband has turned 60 and he's just not as into sex as he once was (and I seem not to be as into it either). He still loves me. He's not having an affair and neither am I. Our kids are grown and we have a great friendship and parenting relationship; I think we're both just in a new life phase. So, cutting a long story short, there are so many different versions of what works.
For yourself, just be sure you're in tune with your own needs. And that the dialogue with your husband is open and he can be honest about his own needs. For 'stability' and the children, maybe there's a version that keeps you together, but if not, divorce does not have to equal disaster for the kids. My parents are still friends (in their 80's) and me and my siblings turned out happy and OK, fully accepting that our folks simply were not meant to be together for the long haul. Good luck!