Am I in the wrong?

My partner and I have been married for 3 going on 4 years.

She came into the relationship with kids and I, having none, have taken them as my own. Their father is a no show and he's got his new little family blooming somewhere else. He's cut the youngest off and the oldest is trying to connect but he isn't interested, so I decided to step up.

Something they seem to care a bit about is having something when their biological parents pass away. Their mom, my wife, doesn't have much in terms of assets or policies. I, on the other hand, do and I've decided to have that be the kids inheritance.

On top of that, I was struggling to find a job a few years ago so I, along with my wife's support, started a company. It's 2.5 years later and we are expanding. Both kids have a say and a job in the business. My wife as well. And when I pass, the business goes to the kids.

That is my intention. For them and my wife to have something to fall back on, should something happen to me.

Fast forward to my issue.

I've never raised or spent time around small children. The business we have revolves around small children and I was left to babysit yesterday afternoon. Needles to say, some things went wrong, the one child broke a glass but with no injuries, the other put paint on a table cloth and somewhere along the line, someone broke the hand soap dispenser.

I honestly tried my best, but my wife spent about 2 hours screaming at me about it. Telling me I'm incompetent and stupid. I admittedly list my temper after the 15th time of her calling me stupid and slapped her hand. Now, she wants a break from our relationship, she wants nothing to do with me and says she hates me. Is upset with me because she isn't living in the town she wants to live in or travel as much as she wants, but we can't afford it because the business is still growing and it takes a lot.

Am I in the wrong to be upset about her treatment of me? Am I missing some kind of point? I just don't know anymore.

The opening of the one section yesterday was meant to be a celebration and an achievement but I feel like she's ruined it all for me because of her reaction to a table cloth and soap dispenser....