Suggest Remedy For Pounding Headache Caused By A Fall

I went to take a shower at 3:00PM and I fell backwards out of my tub, I don't remember hitting the ground but when I woke up it was 3:45 laying with my head beside the sink and my knees bend with the bottom half of my body in the tub, and the tub was overflowing with water and the bottom has a small crack in it. I don't have a cut or even a knot on my head, but my head is pounding with sharp pains. It's 4:41.. what could be wrong?