Pain in wrist, can't bend it back, pain and popping on pinky side what is it?

See details: This is impossible to answer without being able to examine the wrist first hand and order appropriate imaging studies such as xrays and/or MRI. See an orthopedist.

Varies: There are a number of possibilities from abnormalities in the structures in that area including the distal radial/ulnar joint, the tfcc, and the carpal and metacarpal bones and joints on the ulnar side of the wrist. Don’t hesitate to be seen for a thorough evaluation.