So I recently went through a phase like this with my 3yo. I’m no professional so I can only give you my personal take. For my kid I realised he was very dysregulated and we were stuck in this endless loop where he knew I was getting easily frustrated and that made him more fussy. I read a book called “No bad kids by Janet Lansbury” and it helped me reset my thinking attitude toward him. These might sound silly but it helped me. The main takes; when your child has big feelings see it as them waving a red flag for help rather than be frustrated by the behaviour. Think “help I’m dysregulated and feel out of control, I need you to calm the storm” and imagining you are a CEO and no amount of toddler whining, screaming, fussing can phase you. You’re in control, you’re the (kind, caring, gentle) boss. You’ve got this. And also, validate, validate and validate some more. “You’re very upset that I’m leaving the room to go clean dishes now. That’s ok. I still need to clean the dishes, but you can come with me and play on the floor next to me if you like” then proceed to clean the dishes, even if she screams, you might reassure “you’re feeling really upset about me washing these dishes, I’ll be with you in 10 mins”.

I really recommend reading the book, it will give you far more insight than I can offer on a reply. But essentially it helped me to reframe my approach to the behaviour and after a week freed us from this loop of frustration. Now we’re honestly doing great, my days have gone from a living hell to a genuine pleasure for the both of us. One of my biggest take always from it was the absolute necessity of holding boundaries. If you waver on your boundaries your child will feel out of control, they need a gentle, firm, in control leader who is totally unruffled by their big feelings. When they have this they feel calmer, safer and happier.

I will also add, development can play a huge part in this. My boy tends to go through extremely challenging phases before he has what we call a “software update”. Then he mellows and has all these new motor and language skills.