What Causes Headaches And A Bump On The Head After A Fall?

I had knee replacement surgery 2 years ago it got infected and had antibotics spacer place in to help I have used a walker for 2 yrs now so because I can t place weight on the left leg. Now to my question last Sunday I was taking the trash to the garage we have one step down I lost my balance and fell head first to the concrete floor I m no sure how long I was out all I remember is a pop and crack my granddaughter walked in the laundry room which leads to the garage I was just trying to set up dizzy and a big goose egg from the front of my hair line to the back of my head I have had a severe type of headache and my neck is very sore and stiff it is a bad whiplash feeling. How long can I expect to have these headaches it gets so severe I feel like I have a migraine but worse thank u for helping me understand why these symptoms continue and how long is normal. Thank u. Jayne Westbury