I have pain in my back and legs bad what should i do?

Heat, rest,mild meds: Hard to know what might be going on without knowing what brought this on, but you are young so the ODDS are not serious. Try heating pad, hot baths with a little Epsom Salt, acetaminophen or ibuprofen with food (if you can tolerate), and most important, rest up for a day or so. If pain is not helped even a bit, or if you have any numbness, tingling, weakness you should seek medical attention.

Go see ur Family Doc: Typical musculoskeletal back pain usually goes away on its own in a matter of weeks (never quickly enough if you're suffering) so we recommend avoiding xrays etc unless you have worrisome issues eg history of (high energy) trauma/injury, unexplained fevers/sweats/chills, loss of bowel/bladder control. Even sciatica should improve but if pain more than acetaminophen & NSAIDs can manage, seek care

Get evaluated: Hi there, I would like to know whether there is any history of trauma or did this arise out of the blue? For how long have you been dealing with the symptoms? Are they getting worse? What about red flags such as weakness, weight loss, incontinence? Is pain worse with any particular posture? You need to undergo a good MSK and Neuro exam. You might need additional studies such as EMG or MRI.