Big hugs hun, sounds like you have a beautiful but full on little girl. I don't know if I can help much, have you tried just stopping everything your doing when one of her tantrums starts. Just (if it is safe) walk away from her and find something else that takes your focus and seeing what she does?

And the sore leg thing, growing pains perhaps? My 3 year old gets them a lot at the moment. She may have also hurt her leg (muscles) and it was causing her pain.

Maybe you could see your GP and see if they have any reccomendations for you. Or your MCHN?

I hope you get some help soon.