I used to have back pain and I get rid of it by actually finding the source of the problem then fixing it from there.

I used to have pelvic tilt which put by back in over extended position and it become worse when I started to lift weight in gym without fixing that problem first.

I would highly recommend you to go see some professional. In my case, I fix it by correcting my pelvic tilt and add some strengthening exercise to my routine.