We can still talk here if you like. As I was saying, its possible now that she is simply depressed, and the cause is probably more than one thing, its a culmination of things. She could have a fear of getting pregnant again, and thats what turns her away from affection and sex. She turns from the affection because she thinks it will lead to sex. So you'll want to talk to her about some affection and be clear with her that you don't want to have sex, that you just want to have some affection time with her. Full body massages, hand massages, foot massages, laying across each others laps while watching a movie, holding hands, etc.
If you can understand that its natural for a woman to feel this way, and that multiple children can overwhelm most any parent. The most important thing is the communication, which could be facilitated through couples counseling, which is certainly something that should be suggested and considered.
I welcome your thoughts, let me know if you want to talk more