I'm a female, 16, and i have lower back pain bad nausea, gaging and burping, fatigue, and shoulder pain, also i get very tired even though i get sleep?

Low back pain: Low back pain is an uncommon symptom in young individuals. You need to be evaluated by a physician. If you are sexually active, pelvic inflammatory disease is one possibility among many other possibilities. Please see a physician

See your PCP for an: examination and detailed Hx, as from your Hx, one cannot diagnose just one possibility. A Gall bladder inflammation may cause almost all the symptoms, but not all. A urinary infection with shoulder problem may be responsible. To be Diagnosed you need a detailed Hx, complete examination and labs and Imaging modalities. Good Luck and Happy Holidays.