I had the same problem a few years ago. It's not much fun at all. I remember getting up from a low seat was a nightmare which involved me hopping on one leg until the pain subsided somewhat. I tried everything including massage, physio, acupuncture and the osteopath. In the end, it was a chiropractor that fixed it pretty much instantly. I now go for a session every two months and haven't had any major problems since. I didn't like the idea of a chiropractor as it seems quite brutal but it's very quick and really worked for me. You will probably have to make some lifestyle changes though to avoid repeat problems. Things like laptops, bad chairs, bad beds etc all take their toll on your back.
I hated the idea of acupuncture but it's not painful and you feel a bit spaced out afterwards. Didn't do anything for my back pain though.
I hope you can get it sorted soon mate!
Hope you