Leg lifts back pops painfully. 18yrs old back went out. Use to be health nut. Now 30 and still bad daily back pain. What do I do?

See a Dr. This is not a usual story for an 18-30-ish person. You should be examined (and possibly imaged) by a dr to determine if there is some congenital / degenerative / other issue present that can be addressed.