Nah, not tough, totally normal. Newly-multi-childed parents deserve some Real Talk every now and then so they can get over trying to do (and feeling bad about failing miserably at) all the crap they now don't have time/energy/attention for from Internet parenting advice, and get on to counting any day that ends with no more than one bleeding injury per kid and $50 property damage as a huge win, even if it took yelling a couple times and some punishment not accompanied by a bunch of hugging and a long talk about Right and Wrong here and there to achieve such great success. That stuff's fine but at some point you can't be two places at once, and there are more than two places you urgently need to be right this second, so something's gonna get neglected.

It's OK. Internet parenting advice (or any that comes from the latest trendy book) rarely survives contact with an enemy that outnumbers you. That's normal. Be nice and attentive when you can but don't beat yourself up for not taking 15min to calm your 4-year-old down then walk them through Plato's notion of Justice when they're hitting their brother for the 5th time in as many minutes. You have not failed when you have to choose between that stuff and getting the kids out the door to wherever you have to be, or dinner on the table, or clothes washed, or whatever. And when someone else tells you how some system or other they read about on some parenting blog works so great and is so gentle and nice and it's just crazy that anyone would ever yell at their kids for any reason, smile and nod and silently wish them smart, energetic, willful twins next time around.

[EDIT] and it's not the living hell that that read like, now that I look back over that, it's just that discipline problems tend to shoot up the more kids are around and they tend to cluster, and they tend to crop up when you're otherwise busy, for obvious reasons, so when you need to bust out your strategy for dealing with bad behavior it's gotta be fast and take very little of your time or it ain't gonna last long. When things are bad, they're bad. Usually they're fine.

You are over thinking this.

In any life situation, people who have experienced that situation have more relevant than those who don't.