Loneliness of parenthood is real
Stay at home with the kids while wife works and I'm more isolated than I've ever been. Spend all day with little kids and then she comes home stressed from work so we don't really connect. Don't have other dad friends nearby to talk to. Not depressed exactly but definitely lonely and nobody warns you about this part. Trying to get out more and join some dad groups but it's awkward at first.
The loneliness is brutal and nobody prepares you for it. You're doing the hardest job of all day but you're doing it alone. Getting out of the house helps - library story time, parent meetups, even just chatting with other parents at the playground. You need adult conversation.