I apologize for my bluntness but I would say get a divorce. Staying together for kids is not a good idea. Kids pick up on stress. They notice when you aren't happy. I come from a divorced family myself. I believe it is much better to have 2 happy parents that are separated than two unhappy parents together.

Alternatively you could suggest an open relationship where you could sleep with other people. This works for some. However it does not solve your unhappiness factor.

I guess I should also ask if there is any chance she is depressed? Though it sounds like your marriage has always been like this. Perhaps counseling may help?

Personally sex even once a week wouldn't be enough. Once a year would be a deal breaker. From her perspective, I wouldnt want to have sex with someone I wasnt attracted to either.

So I guess my advice would be to consider splitting up. Why prolong the inevitable.