I'm concerned for you, please talk to your parents and have your primary doctor refer you to a neurologist; get an MRI scan of your C-Spine. I have had more than one head injury, resulting in concussion and an important factor in concussion that can be overlooked whilst we concentrate on the concussion symptoms is that the head balances upon such a fragile stem - whiplash often accompanies head injuries, and those that are impacted at such a force as you experienced can result in C-Spine injury.

I have all the symptoms you describe after an auto injury when I was 22. Read ended by a drunk driver while my car was parked. I didn't seek medical at that time because I was in the Air Force and feared being discharged (intuition must have told me it was a severe injury). I am now 46 and the simplest of tasks like washing myself in the shower, shopping, making dinner, reading a book... anything that requires the head/neck to be fixed in a position other than looking forward, results in the symptoms you describe, nausea and vomiting due to C-Spine "Cord Impingement" - swelling around C4 which puts pressure upon the spinal cord.

Encourage you to allow your parents to love you to their fullest potential, and allow yourself to be assured your intuition to take care of your health is right on. You're an overachiever so your nature is to override any 'weakness', I get it, believe me.

... tell them. Get this taken care of with the same overachiever gusto you go into those games with. Quality of life should never be forfeited. Be your own advocate as you're doing by seeking advice. Proud of you!

Love to you