Sex drive has vanished

I don't know what to do. I've tried making myself get in the mood. He's tried everything he can think of, and nothing works. I am 6 months postpartum, and of course, my body has changed quite a bit since having two kids (appearance and weight wise). I can't stand to be naked in front of him. Most of the time, I cringe and push my husband away if/when he touches me. It has really put a strain on our marriage. He thinks it's his fault, but it's not. It's me, and I don't know why. It hurts me more than he thinks it does because I feel like a horrible wife. I've tried explaining that to him, but he just thinks I'm bored of him when I'm not! Please help me!!