Sounds chaotic!!

I am not sure what to suggest about the big picture, but I did managed to put an end to my DD's biting at about 10/11 months by following a logical consequences approach. Every time she bit me, I yelped out loud (didn't have to make that up, it hurt!) said, "no, don't do that it hurts mum", and then put her straight down on the floor and turned away from her. She would always look startled and sometimes got a little upset. After a few seconds, I would treat her as per usual, pick her up and go about normal life without making a big deal. I had to do this about 4 times and then no more biting.

I would do the same thing with the headbutting or, I guess, any undesirable behavior based on the fact that toddlers want to interact with you and if this interaction is removed from them, they learn pretty quickly to engage in more desirable bahaviours. If you yell, punish, interact etc they continue to get your attention which is a positive in their mind even if it is negative reinforcement.

I hope you work something out pretty quickly, and your little girl picks up soon. I imagine your house feels a bit mad at the moment.