About 3 Weeks Ago I Slipped On Ice And Hit

About 3 weeks ago I slipped on ice and hit the back of my head pretty hard I blacked out for a minute when I came too I couldn't talk or move for about 3 or 4 minutes i was very dizzy and my vision was blurry after I was able to get up I was dizzy for a few minutes since then I've been getting very bad migraines I've been very tired and I have a dent where I hit my head I should of went to the hospital but I didn't can you tell me why i have the dent and what's going on with me please