What should I do to get rid of my back pain?

It's a shame you didn't see a doctor the first time. But you really need to see a doctor this time. Especially since you're a dancer. The doctor will probably do an x-ray but hopefully you can also convince him if the X-ray doesn't show much to do an MRI. That's to make sure nothing serious is going on. Then he should send you to a physical therapist. The physical therapist will just give you exercises that you can do to help strengthen your core muscles which since you're a dancer you probably already have pretty strong core muscles. But the PT can help you with your balance and teach you how to do things that will not put your back out. An example that I can give of that is when my back was getting worse I couldn't pick up my grandson who was just a little bit of a toddler and small for his age. Well my PT explain to me that if I have him climb up on the couch and I pick him up from there rather than from the floor I'm less likely to injure my back again. So that's the kind of help that a PT can give to you. You sure don't want this to get worse. I've lived with horrible chronic back pain for 13 years.

Hi, being so young and having sharp acute pain I would definately seek Dr Advice and going to see a chiropractor as in some of my early stages through sport my back needed alignment. As you dance your body will move in ways it may not be naturally used to. Worth a visit to both. Good luck x