What do y’all do for discipline for misbehavior/disobedience that leads to accidentally hurting baby brother/sister?

My 3y/o is SO strong willed. I have told him countless times to not lean into brothers rocker. He leaned in while I was trying to help my littlest to sleep and slipped and covered his face with a lot of his body weight, thankfully I was RIGHT there and shoved him off right away and shouldered most the weight that pushed into my hand that was stroking brothers face. As he was starting to lean in I told him to stop leaning into the rocker and to back up, sternly, he doesn’t listen until it gets to the point of me having to physically remove him. This is one example. Others are jumping around brother, throwing toys, etc. I sound like a horrible mom but I try re routing, time outs, etc. and none of it really does anything to where he actually feels remorseful about his behavior. I’ve tried swats even for the serious stuff like intentionally hitting brother or intentionally disobeying to the point of hurting his brother or potentially hurting his brother and they don’t do a darn thing for him. Helllp please. I’m also a single mom, so it is JUST me.