Lots of excellent feedback on this thread (except for the legally inaccurate and morally unconscionable posts from shoal007). Here are my 2 cents...
Please do consult your doctors. I don't know you and know nothing more of medicine than the next guy, but from your descriptions the risk of hidden/delayed injuries seems a real danger. Document every visit and cost of course.
DO consult a personal injury attorney. It won't cost you a penny. If a PI attorney thinks a civil case can be made he'll help you document what happened, corral witness testimony, etc. Hearsay and other non-direct evidence IS admissible in civil courts, so the case may be stronger than you think. An attorney may also recommend pressing criminal charges, either because the evidence is strong or simply as a tactic to bolster the civil action. Please consult an attorney SOON... the clock is ticking. In legal and insurance claims, time is the enemy of the claimant. The longer you wait the lower the odds of any action being effective.
Filing a civil claim would also enhance the prospects of your own insurance subrogating against the perpetrator's insurance. That would put another ally in your court. The main difficulties would seem to be establishing proofs and identifying attachable assets or insurance. A PI attorney has the incentive and (hopefully) expertise to do both.
We've only heard your side of the story but based on what you've posted the kid's liability seems unquestionable. His actions violated multiple tenets of the Responsibility Code (skiing out of control, failure to yield the right of way to a skier downhill from him) and lacked common sense. Legally, this constitutes negligence, which makes him personally liable and triggers coverage from his insurance (if any). (Speaking roughly, "negligence" means behavior that ignores common sense or commonly accepted standards of behavior for non-experts, like the RC.)
Further, a resort employee is presumed to have been trained to a higher standard than the general public, which may allow your attorney to argue gross negligence. (Speaking roughly, "gross negligence" means behavior that ignores rules of which a person has special knowledge, knowing that damage might result.) Gross negligence is a more serious breach of legally acceptable behavior than simple negligence. If a civil court finds gross negligence it tends to increase the probability and size of any award. Punitive damages are typical in cases of gross negligence, they're rare in cases of simple negligence.
Note: the resort wouldn't dare defend an employee from a charge of gross negligence by (for example) understating his training on safety issues. That would open THEM up to charges of gross negligence or perhaps even criminal liability (depending on the laws of the state). The resort would probably act on your side in such a case. They'd present records proving that the employee received safety training in an effort to limit their own liability. The perpetrator would be legally skewered from all sides (as he should be).
As some others have advised, do NOT interact with the perpetrator in any way. You'd put yourself and your case at risk. Do not harass him, verbally or otherwise, directly or through the misguided efforts of well-meaning friends. That could significantly impact your own credibility in any legal or insurance proceedings or even subject you to legal counter-actions. Regardless of the provocation, we all have an obligation to remain reasonable. You have been entirely so and I commend you, but in my view you've also been overly accommodating. The perpetrator and possibly the resort (especially if he's an employee) need to be held accountable.
I'm not an attorney but I work in a corporate legal and claims environment. These situations often result in settlements even when proof at a criminal level is lacking. Please consider pursuing this. If nothing else, your own anger and peace of mind may be aided by knowing you did all you could reasonably do.
Best of luck,