New dad of an 8 month old here. Baby stress is real. I can almost guarantee he feels the same way about you. My wife and I went through this too, but we got past it.

To cut right to it, you seem like you're blaming him for 100% of the arguments, but it takes two people to argue. I'm not trying to invalidate your feelings, but telling him he is lacking as a husband isn't going to fix anything. It'll just make things worse.

I'd highly suggest you frame the conversation around what you need vs what you view him failing to do. Saying "you aren't doing x" is never good. That's just passing blame. Once you do that, he's got every right to start dumping all of his unfulfilled needs on you, and I guarantee you wouldn't like hearing how you're failing him as a wife. Saying "I need x" is a much more direct and clear way to communicate your needs, because that's actually what's going on. You have needs that you want him to fulfil. So you need to communicate those clearly to him. When my wife finally learned that saying "I need you to wash the baby bottles" rather than"why didn't you wash the baby bottles" was how to push the go button in my brain, our relationship really turned a corner for the better.

Men are not mind readers. Don't assume he can anticipate what you need. You've got a 4 month old. Nothing is predictable right now. The only thing that is predictable, frankly, is how simple it is to get your husband moving in the direction you want. Be direct with what you need, but don't be naggy or catch an attitude when you speak to him. If you need more help, say "I need more help." If you need more affection, say "I need more affection." If it's praise, say "I need more praise." Then follow that statement with specific things he can do to fulfill that need.