I hit my head and I think I have a concussion?

I was in my kitchen & I slipped on the floor and fell flat. I landed on the back of my head & I smacked it real hard on the floor, & now, about 2 hours later, my head hurts. It hurt really bad when I fell & I was dizzy & I'm still kind of dizzy but not super dizzy. When I look around I see spots like I just looked at a light bulb or something & I have a really bad headache in the front of my head. I feel like tired too but idk if I should take a nap or not.... Help? Opinions on what I should do? It was some of the worst pain I've ever felt in my head.