Wow these comments actually helped a lot! I'm probably going to keep off the snow this season to heal and finish off my volleyball season. I guess I just want my parental units to understand that no matter the injuries snowboarding is my favorite thing in the world and I never want to stop... I know that my parents just want me safe, but being a teenager, sometimes it feels overwhelming and I just want them to lay off haha.
We've all been there, and some of the posters here have/had teenagers of their own. It can be hard to understand the perspective of our parents, but it is their job to protect us and raise us into productive citizens. Snowolf and the many of the other posters have offered some very solid advice, but I think we can take it a bit further.
As others have pointed out there are risks involved in many of the things we do, but I think we can all agree that park riding has a much higher risk/reward factor than most of our day-to-day activities. Especially for those of us who will never, ever, be X-Games competitors whose livelihood is attached to our ability to throw our bodies around with much disregard. Concussions are serious business, and even more so for demographics who's brains are still developing (such as yourself and other young people).
If I were in your shoes I would start with some of the things Snowolf brought up (e.g. there is inherent risk in everything we do), but I would also acknowledge that this is a riskier activity. Then I would discuss some of the things you feel you can do to minimize and/or eliminate (to the degree that we can) the kinds of risks inherit in riding park. Things like sticking to the philosophies of "easy styling it" and buying a new helmet to replace the one that is most assuredly busted from your last accident. This is a more thoughtful and mature dialogue beyond the cursory "I love doing this and I don't want to stop."
You need to recognize and own your parents fears and worries because otherwise you won't be able to change their perception of you as an "idiotic reckless teen who doesn't care about her health." Only you know if the injury was caused by an accident (e.g. you were doing a trick you have on lock and hit a bump or a nail or whatever and it busted you), or if you were riding beyond a safe range for your abilities. So, think about that deeply and enter into the discussion knowing that they want what is best for you, but also recognize that YOU need to start thinking about what is best for your health.