You will always here a lot of horror stories concerning backs I’ve suffered on and off for years,I’ve tried physio,chiropractors,acupuncture,I’ve had epidural injections,sacroiliac I njections and a micro discectomy and I still suffer now,albeit on a tolerable level.No two people are ever the same what might help one will do nothing for another,I agree with conor sitting for long periods is the worst thing ever,for me keeping as active as possible is best,as for an injection after a week you haven’t got a chance,this can only be done with a consultants consent and it will be a few weeks before you see one,unless you go private.On the positive side most people do get better it just takes some longer than others,best of luck to you,stay positive.