My husband says our relationship makes him lonely? I need advice?

My husband told me he’s lonely with me, and I don’t even know how to process that. I feel like I’m living with a stranger, he’s distant, mopey, and it’s hard to be attracted to that. But hearing him say he’s lonely hit me like a punch to the gut. I’m 21, married, and yeah, I’m attractive, curvy, long hair, smooth skin, and I’m definitely not lacking in looks. Part of me wants to fix things, but another part wonders if we’ve already given up without saying it.

So, guys, what do you do when you feel like you’ve lost connection with your partner? Could he be seeing someone else, and that’s why he’s distant? How is it possible for a guy to be unsatisfied when he’s married to someone who’s literally been called a "15/10" by our pastor? I just need some male perspective, feel free to dm me if that's more comfortable. Thanks.