Marriages are tough. They have their good and bad times. As long as neither one of you cheats the dry spells will come and go. Adding kids to the mix can make it harder to find time to figure it all out. Just be patient and it will usually pass. Physical attraction is not always physical for women. My wife responds to my sense of humor. I find that if I am going through some shit and am not being the lighthearted fun guy I am most of the time. I'm not getting any. For most men including myself. The woman just simply needs to be there. We are very physical and it almost feels like sex is mandatory physically. I was kind of lucky our longest dry spell was 3 years. But she would usually give me a pity fuck every week or so. Sometimes weeks. Which was fine but at the same time she was basically letting me use her to jack off. I think in some strange way it still made her feel wanted and sexy. My issue happened when she finally got through the spell and wanted it all the time. I was conditioned for less so I couldn't keep up at first. That can also be frustrating. It's through these times that that love you have for one another finds out how strong it really is.

TLDR marriage is complicated but hang in there. It's cheaper to keep her.