No sex

So since the birth of our fourth baby who's just turned one me and my husband have had sex ONCE. Despite me talking to him about it on numerous occasions. He keeps saying he's busy. Busy for an entire year?? I'm so frustrated. Our kids are all great sleepers so no problems there.

It's not even just sex it's like all the intimacy is gone. It truly feels like he's my roommate. He's refusing to acknowledge that there's a problem. Won't go to couples therapy. What do I do?