Emotionally distant SO

So ever since we found out that we are having a baby my SO has been emotionally distant. When I told him we were pregnant I barely got a reaction (it was his birthday). Then when we found out that we were having a boy I got the same “oh...cool” reaction. I found out he was having an emotional affair with a coworker in January but he ended it a sought out therapy. He’s rarely even shown any excitement at having a child and now I’m sitting here at 35 weeks depressed and sad because I didn’t get to celebrate with my SO the way everyone else has. I know jealousy is an ugly thing, but I feel so robbed of being happy during my first pregnancy. He’s just withdrawn so much that we barely speak and he’s always playing games on his phone or sleeping. For reference he is 22 and I am 28. He’s usually super mature for his age. But lately I can’t help but feel like he’s regretting trying to have a baby now that it’s becoming real life. Has anyone else had this issue? I feel like I can’t trust him emotionally to be my support person when I go into labor. And in the times of stupid COVID the thought of that sucks. 😢