When I was 22 I did something to my back when I was lifting a heavy weight. It put me in bed for a few days. Every now and then I get the same effect and it can be just from doing a very minor activity. I saw a physio a few years back and she kind of massaged each of the cartilliage up my spine for about 30 minutes. She gave me exercises to do also and said she would be able to cure my bad back for good if I did the exercises. I didnt do the exercises because I wastoo embarassed at work. Now I am thinking though would it have cured my back for good if I did exactly what she said and would it be worth going back to a physio again?
Same problem i faced in my life.
When i was in school i participated in long jump sports and when i was playing i got a heavy jerk on my back.
Since then I am facing this lower back problem. Then I visited physio, he gave me oil for massage and few exercises. I started doing what he said and I am better then what I was before.
So I would advice you to go and visit physio again and do what she tell u.
You will get well soon.