5 year old tantrums

[Cautiontothewind]

I am at a loss with my 5 year olds behaviour at the moment. As in I'm really struggling with knowing how to deal with it, I'm not even sure it's normal tantrums anymore.
If she is told no or doesn't get her own way she full on rages, shouts at us, calls us names like rubbish/stupid, stamps foot, throws stuff. It's so full on.
We've tried the nice approach, the big cuddles, talking etc. We've tried taking things away, we've tried ignoring. She literally does not care.
She fights with her older sister and I do think she feels constantly in her shadow.. But we don't know how to resolve this as we tell her she's amazing, good to be different, treat them fairly and have 1 on 1 time. Her older sister does wind her up and we try to be on this, we also at times leave them to it depending on the situation.
But it's got to the point now I am struggling so much to deal with it all. The girls bicker constantly which drives me mad and tbh neither seem to respect us. But the tantrums of my 5 year old are another level and I don't know what to do! Anyone have any tips at all?

Sounds very familiar.
You've mentioned most of the things I was also told to try, also to no avail.
Have you tried labeling her feelings and saying it's okay to feel like this but it's not okay to act like that and tried some breathing exercises or a dark den to calm down.
I have to say this has helped us a bit, the tantrums are definitely still there and still daily but there are certainly fewer and they seem to be getting shorter in duration.
Good luck!

Second amiayoung's post.

Just wanted to add this article on anger from a Mighty Girl as it references some books which might, or might not, help

Thank you both, will take a look at ths article and also try the other things mentioned. At the moment we also have a lot of arguing between the 2 kids so that's exhausting as well lol