Is it more muscular or mechanical (bone) pain you are getting? Whereabouts in your back?
Back pain is miserable. I used to be prescribed co-proxamol and it really helped me. Co-dydramol in the past too. There are stronger ones like tramadol which will more knock you out (be very careful if you end up on those kind of drugs) but depends on the cause as to how effective it will be - whether you need to wait it out or something needs to be done to fix it.
I was going to suggest diclofenac, good stuff though be careful with these kind of drugs if you have a delicate tummy, make sure you don't take tablets on an emply stomach if you can help it, Zantac can help too. Also watch if you are using any pain gels or similar as many of them contain drugs like diclofenac as well.
I've had a lot of help from osteopaths in the past.