“My husband and I were happy until the birth of our son when our relationship changed. After our son was born he started cheating, lying, and drinking everyday. We spent less time together than we used to. I thought we were friends, but now it feels like we are distant cousins. Our sex life is boring.”

Take up your life
Please read David Schnarch’s book entitled Passionate Marriage. I will warn you that it is the very best book on sex and relationships I have ever read. While it is graphically sexual, it is never pornographic. It is to be read as a whole, cover to cover, before judgments are issued on its worth.
The book outlines the journey of couples who have lives as miserable as you describe yours to be, and offers valuable keys for all marriages and relationships.
I have gotten into trouble for recommending this book to couples, not only because it promotes very strong and healthy sex lives, but because it challenges people to live full, complete and adventurous lives.