He says that somethings different now...

So I had a baby almost two months ago and at first the baby brought my fiancé and I a lot closer, but recently we’ve been spending more time apart than together. Today he said that he feels as if somethings different between us. That we still love each other but it feels different. I don’t know what to do I don’t want us to split up I want the sparks back in our relationship but I don’t know what to do. Right now I’m terrified to have sex and he tells me he doesn’t miss it. I feel kind of lost and sad...any advice?