My son is going through the same thing and before all this would only have a tantrum once in a blue moon so it does feel like a huge shift. I would say I was previously quite a gentle parent but I have come down hard with consequences now and things like the hitting have stopped. You have to follow through with any consequence you give though or it will just backfire. I also considered getting one of those reward things that you fill up (a jar with Pom poms ect). Instead of focusing on the negative behaviour you reward the good behaviour with letting them drop something into the container. When it’s full they get a treat. I’ve used it with my reception class before and it works well. I haven’t started with my son yet though. I keep saying I’m going to but I’ve got a newborn too so haven’t gotten around to it yet. I’m sure it is just a phase, Ive heard the new term for them is ‘threenager’ and it definitely seems appropriate. I hope this phase is over quickly for us all!
My son is 3.5 and going through the same thing, and I think so many others are when they are this age. Which I know is reassuring but doesn't help much. I think it's a case of riding it out but still being consistent with boundaries in the hope it pays off once this awful stage ends. I find myself staring at a blank wall for hours after he goes to bed trying to regulate myself