Your kid doesn’t hear “I need a few minutes to deal with my human feelings,” they hear “daddy is mad and doesn’t want to play with me.” They don’t have the emotional intelligence yet to understand that you’re a person, not just the mythic figure of parent that they see.
This is why the trope of daddy taking a minute alone on the toilet is A Thing.
On the upside, you’d be surprised how often you can destress precisely by being a kid with your kid, playing Legos and cuddling. Being a dad is hard, but it’s awesome.