There's a reason why most relationships break down in the first few years of having a child - because its fucking rough!
Both your lives have been uphauled, and things forever get more difficult. But its important to keep telling yourself, and them, that you are on the same team - fighting the same financial worries, same lack of sleep, same work issues, same cleaning issues etc.
Resentment is so easily built if you think of it more I did this so I'm really tired, more so then we are really tired today
Me and my partner went through this, still do now and then. But we sit down, have a talk about how difficult we are both finding life right now and what can the other do to help. No raised voices, no blame, just how can we help each other.
Most of the time, that conversation is enough - just to be seen, heard and valued.
I know you probably don't want to because your feeling stressed too and think why should I, but someone needs to make the first step. Is there anything you can do just to show a little love for your partner to open up this kind of conversation?
Can you run him a bath when he doesn't expect it, or cook his favourite meal and light some candles to make it more special? Just do something unexpected, something loving, something that makes him feel seen and valued, and then try the conversation from there. Hopefully it will be the start of your partner doing the same for you - but some one needs to be a role model so to speak