Painful Botox and nerve irritation - what could this be?

I had Botox in the upper half of my face.The first round was severely painful. The stinging I expected, what worried me was the headache that increased with every shot. I probably had 10 shots altogether and by the last one my brain was violently throbbing! It felt like the injection was taking up space in my skull causing a pressure headache (I know it can’t be that). I also had nerves reacting with every forehead injection not the needle, the serum. Dr was dismissive, said ‘normal’. It’s not!