here's something I can help with. I injure myself almost every month and have been doing it for years.
what schaden said in the top 1/2
what wombat said
however, prior to see seeing a chiro see a licensed masseus. it may well be muscular and she

should be able to tell right away.
if not muscular then a chiro is a good place to start. while the holistic approach to healing is pooh poohed by the "real doctors" every one of my sports related injuries has been best treated by the holistic approach.
Good luck, play hard it keeps you young. albeit painfully at times.