Just wanted to say that my 4YO (5 at the end of the month) DD2 is exactly the same; like yours she has been like this since a baby.
She is a beautiful and lovely little girl, but can be so, so stubborn.
Tantrums like this can start from first thing in the morning - if a pair of pants aren't 'comfy' or 'the right ones' and we haven't got time to change then she will literally go absolutely mental and even once she has managed to get out of the tantrum, she will continually go on and on and on...
My DD, once in a rage, will start biting herself, banging her head on the floor, pull her own hair etc etc, but she has started this new thing where instead of just shouting around, crying and having a strop, she will actually scream over and over again, its as though she is being murdered or something; and it is sooo hard to listen to it too.
The new screaming business usually leaves her hoarse, with a sore throat, bright red and with sweat dripping down her face from all the effort!
When she used to be sent to her bedroom she would strip the beds, pull all clothes out of wardrobe and drawers, tip dolls house upside down - basically destroy her bedroom.
I don't know what techniques you've tried already, but we've tried virtually everything. Instead of sending her to her own bedroom, we stripped down a spare bedroom to literally nothing (i.e nothing that she can throw or hurt herself with) and she is sent there to calm down. Recently she has started needing me to go and calm her down, whereas before she would stay there until she stopped - no matter how long it took, and would go crazy if I went up to see her/calm her down. Often she will refuse to go to her bedroom, but I will just carry her up regardless and put her in the spare bedroom - I then calmly tell her that she can 'come downstairs when she has calmed down'. If she comes out then I just take her back to the room - never getting angry, but firmly telling her that she needs to calm down. This basically continues until she stays there and calms down.
Like I said, the past few weeks I have been leaving her on her own for a while, but then going up and asking her if she wants me to sit with her (a few months ago she would have screamed at me to leave her alone). I try not to cuddle her (as harsh as that sounds) as it may be seen as 'rewarding' her for bad behaviour, but at the same time she needs help to get her out of the tantrum.
Once totally calmed down we talk about how silly it is to get so angry about something, and she is made to apologise.
We've found the worst thing to do is shout, I know that it is sooo hard not to because they are going absolutely crazy - but all it does is start to annoy you and get you more angry, and then DD will start sensing the anger and will wind her up even more until all of us are worse than we were at the beginning! Its important that they know you aren't happy, but at the same time getting angry is virtually pointless.
I know this hasn't been much help OP, but its sometimes reassuring to hear from other parents who have wild animals too! 