I'm coming back from crazy lower back pain (mine due to very tight psoas muscles) because my core is shit weak especially my transverse abdominis. I recently started doing Hollow Body Holds, L-Sits, stomach vacuums and a some very slow reverse crunches once my lower back pain went away.
Omg back pain is the worst. Try Lidocaine patch or biofreeze gel, they have it over the counter at CVS or Rite aids. Those help a lot. Also consider a back brace. I messed up my back playing sports and I find wearing the brace help relieve the pain alot.