Male perspective here: Agree with above - been there, done that, have the t-shirt. . .the marriage is essentially over when he declares it sexless for no legitimate reason (like let's say a Christopher Reeve type of situation).
Let me also add a religious perspective (and BTW, I am not a reverent person. . .just find the study of relgious doctrine interesting).
I am not sure how you were brought up with your religious views but I was raised Roman Catholic but now consider myself "intelligent designer."
Anyway, you know how uptight Catholics are about sex. Just about no circumstance can you have sex and even in marriage, it's supposed to be a "marital embrace", not an act of lust.
Anyhoo, knowing how uptight Catholic doctrine is about sex. . .wanna know what I beleive their position is (I am not an apologist)?
For the marriage to be valid, it must be in a state of consummation. Consummation is not a one time act your husband did on your wedding night. IT's a constant, ongoing process. Now. . .of course there are differences - as you note - a 4-7X/weeker vs. a 2x/monther. . .both are states of "consummation." You can change up and leave because of a different libido.
That being said, his choice to not consummate his marriage is effectively annulling or invalidating your marriage. It doesnt' exist. In fact, annulment means it never existed.
It's a "wifely duty" and a "husbandly duty" to the marriage. I use that word "duty" becuase to me, it's a pleasure. My stb-x invalidated our marriage in that regard.
Now. . .as far as children and going through the divorce, let me say this, only speaking as a father of a 3 boys spread apart in ages (youngest is 20 months - long story how that happened in our sexless marriage - can you say I am extremely lucky - 1x/year ???
). Out of all the parties who have had to handle it, honestly, they handle it the best. Truthfully, I think it's been hardest on us, harder on the grandparents, and easiest on the kids. The kids just want to know that they are safe and their environment secure and they at least get to see the displaced parent a little. Of course, I may not be privvy to some internal suffering but it really is true when they say, "Kids are resilient." It's not just something they tell you to make you feel better.
Feel free to private message me with any more concerns.
All this being said. . .all this being said. . .let me say I wouldn't wish divorce on my worst enemy. It's horrible. I would plead with him first, like I pleaded with my wife to not have to not pull the trigger. Don't make you do it.
Divorce sucks. . .whether you are the leaver or the left. No party gets off easy.