I had block shots in back & had no pain. then did ablation on my back & have worse pain now. why?

"Block shots" can be "trigger point injections" or using anesthetic injections into spinal nerves to test if ablation (a more permanent treatment predicated on "good results" from spinal nerve anesthetic injection). True ablation procedures may cause inflammation, leading to usually temporary increases in pain. Obtain a referral to a back specialist orthpedic physician or a neurosurgeon.