Steve's post regarding long-term considerations are concise enough i guess.
But for the short term aid for your problem, might i suggest GOOD QUALITY ankle and knee supports. McDavid is a good brand with product offerings for stages of an injury. I advise that you do not scrimp on these. Of course, if you do decide to get supports, please dont spoil yourself wearing them forever. They need to come off after some time. And please try to go see an appropriate doctor, you might find a way around it without bothering your parents.
I would say no to supports.
Firstly, if you're a teenager there is NO reason you should be needing these in the first place.
Secondly, supports do NOT fix the problems wrong. They just mask them.
Thirdly, the cost money.. which you don't need to spend.
Basically, you don't need them provided you're actually conditioning well and not being reckless. Backing off and listening to your body as overuse starts to occur. If you train smart, you will have a healthy body without need for supports at all.