hi, sounds like a disc prolapse or protrusion. what about slight mobi and bedding the pat. in side lying (right side) with a chusion under right side and knees flexed 90°. is pain decreasing? i used that in acute pain and it worked pretty well. you can also start with some pelvic floor and core muscle exercises and active mobi of LS from this position.
also little massage/friction and stretching of lower back muscles might be usefull, sound that they are in spasm (limited flex).
good luck