How to comfort your husband when he's sad?

Please don't hate me for this but this is my husband's account he's sleeping right now me and him are having our first baby in October he's scared that our kid will have to spend their life in a bubble we watched a documentary the other day about the boy who lived in one I think it upset him a little also between him having his own health problems and him being younger than me he has a lot going on right now I think it worried him. I hate seeing him sad it worries me he's acting like he doesn't want it he said he does he's just worried. I keep telling him there's nothing to worry about that there's 1 in a million chance of our kid having to live in a bubble. How can I comfort him? What should I say to him?
How to comfort your husband when he's sad?
Post Opinion