It does make sense. It sounds like you have had a very tough 2020 - new baby, social isolation, DP's bad moods.
You've talked to him, obviously, and that hasn't helped. It sounds like you have reached a place where you are considering separation yourself. You need to get yourself into a position where this is a realistic possibility.
How are you placed financially and for practical support? Do you have family nearby? Is your business viable? Do you have savings?
In the meantime I would be very cool and calm with your DP. Don't react to his moods. If he is grumpy, say to him, "would you like to discuss what is bothering you, as you seem to be really angry today?" If he shouts back, or denies it and blames your over sensitivity. Just say, "ok I see you don't want to talk, and I won't stand for you being rude to me when I only offered to help. I am going to go and do xyz then." And walk out of the room. Just keep doing this, with small variations in your side of the dialogue.
If he follows you and tries to keep arguing, then turn calmly to him, look him in the eye, and say, "you're picking an argument. When you do that it makes me really upset. I'll tall to you when you can talk with me reasonably."
Don't engage with him at all. The rest of the time, be completely calm and nice, but assert yourself - don't take any crap from him, and don't clip your own wings to appease him.
Make sure he does a reasonable amount of childcare and that you get time to yourself. You should find Facebook groups locally where there are other trapped mums and dads of toddlers who just want to meet up for a walk. My local NCT runs weekly walks for this reason, for exams. Having friends IRL would help you, I think.
Once you have all your ducks in a row, then you have the option to leave him.