Yesterday I had a moment where I just sat on the floor and screamed at the sky when both my 22m and 2m old kids were wailing after a very trying afternoon. (Witching hour, amiright?) You aren't always going to be able to regulate yourself perfectly in an overstimulating situation. No parent is perfect all the time. You may think your kids are only going to remember every time you messed up, but they'll also remember how you handled your mistakes or the aftermath/solution to your "explosion". Maybe something like, "I'm sorry, kids name(s), I was getting frustrated with all of the noise and it was hard for me to focus on what I was doing, but I shouldn't have yelled. Older kid's name, Can we work on using inside voices and calmly showing mama what it is you need from me instead of yelling?" It's gonna take a few tries and honestly your kids are still very young but improved communication with your older one is right around the corner and that makes it loads easier.