I have a feeling I have a concussion but I'm not sure?

I was at the Kalahari yesterday & I jumped into the water & started to swim underwater when some big lady smacked me right in the side of the head. I don't know how she hit me but she hit me pretty hard. I just kept swimming after she said sorry & nothing really came of it. Then when I got home I was extremely tired so I went to bed around 10:00 which is not normal for me. I started to get a horrid headache that I've never gotten before. I thought nothing of it & just tried to sleep it off. Then the next day at school my eyes really hurt, my neck ached really bad, and my head hurt. I couldn't keep my eyes open & around 6th period I was still tired. That was not normal for me, normally I have woken up by then. It felt like my head was a giant boulder & my head was a little stick. It hurt & it hurt for my head to move quickly. I'm pretty sure I have a concussion but I'm not 100% sure. I need some input. Do I go to the doctor? My mom says she thinks I don't have one & my neck & head are just "sore" from the blow. Do I sleep it off? What if it gets worse? HELP!?!?!