There's something wrong with my husband

Hello mommies

I'm not sure if it's okay to ask about it. It's kind of embarrassing for me, but here it goes.

I am happily married to my husband and we have cheerful and fun-loving kids. I don't think there's something I could ask for. I'm happy with my family. However, I somehow noticed some things with my husband.

A few weeks ago, before my eldest son's birthday, my husband seems strange. He doesn't kiss me anymore. He doesn't seem to talk to me for more than half an hour. He never tells me things about work which he usually does before. He's always tired. We haven't had sex for more than 2 months now. I asked him a couple of times if there's something wrong. He just responds with "nothing. should there be a problem?"

I'm not getting him. Do you think he's hiding something? Is my relationship hanging?