Sharp sudden pain lwr r abodmen + lwr back.fever, nause, vominting, oxycodone not working w/ pain, can't walk+sleep, lost appetite. what can this be? help?

Ovarian cyst, GI eme: Given your age, and the location of the pain, a gynecological cause (such as ovarian cyst or torsion) is a possibility, though you could also have a GI emergency. I would recommend seeing an md in an urgent care clinic for exam and possible imaging if this problem has not resolved by now.

Possibilities: There are several things that this could be, many of which are surgical. You need to go to the ER and be evaluated sooner rather than later.

Abdominal pain: Abdominal pain in lower right abdomen which persists needs to be evaluated by a physician. Even more concerning is that it worsens with walking, no appetite and not helped by oxycodone. You must go to the ER right away.