I would not accept any of what you are putting up with OP from my 14 year old DD. You do not need to either.
My DD knows that her actions have consequences. Sometimes she has had to learn this the hard way. Do I like imposing consequences, no of course not, but I am her parent, not her best friend and her Dad and I have a job to do.
If she chucks a teen tantrum because you say no or she can't get her own way. So what? You are the parent and you control and pay for her food, clothes, WiFi etc.
Consequences - for teens, need to be something the value dearly and relevant.
DD- has not put her school uniform or netball kit in the laundry to be washed .It is still on her bedroom floor where it has been since Friday after school. She was told to put it in the basket Friday night. DD has not, it won't be washed now and she will not have her netball kit ready for her after school match tomorrow. If she decides to stay up and wash her uniform/ kit fine, but I won't be and I won't be advising her on laundering it either. If she wants to attend school in unwashed uniform tomorrow that's on DD . I have emailed her head of year in advance and explained the situation. Tomorrow morning she will probably kick off . If she tries that I will calmly explain my position and she will then have her phone taken off of her for being rude.
The physically attacking you needs to stop right now. You are going to have to be really tough on that and have a zero- tolerance attitude to it.
In my house DD would be grounded with no tech/ WiFi for a week, no clubs or seeing friends for a while . She could have time to reflect on her behaviour.
yes, DD has tried the I will be bored without the internet, I need my mobile to contact you or Daddy.
My response tough luck it's not happening and I will not change my mind, whilst handing her the basic flip top mobile phone we keep for an emergency.