[Maryanne]

A females body changes when she has children, sex becomes mechanical if not at all.Looking after the children takes away the desire. If you had a good sex life before marriage, it is possible again, but you need to get away on a holiday and find a way to talk it through. You will find viagra and cialis work just as well for woman as men, but go to the doctors and get a very low dosage, spend a little time getting to know each other again and the great sex can come back, and if you keep the talking going it doesn't have to retreat once you get home.
Your wife will be as confused as you are, and have no idea why she has changed its just nature at work.
Once the kids have grown woman come back into their sexuality around 40, by that time if the comminication lines haven't opened up...you will end going different paths.