I'm having trouble with this myself. I have a 3yo and a newborn. DS1 is a really sweet little boy who is rarely intentionally naughty but I'm just so freaking tired that I have no patience at all. I hear myself sometimes and I don't like what I hear.
So I get it. We know it's all hard for them too and their behaviour us normal for toddlers. That they're good kids who deserve patience and understanding. For me, at the moment, I have zero reserves and very little patience.
I'm accepting help from pretty much anyone who offers, particularly looking after DS1. I think it's best until I'm getting more sleep.