This is a good step for you. They’re taking into consideration your degree of pain and they want to provide you with relief so you can move onto the next steps. The inclusion of an anesthesia to help you tolerate the procedure is a plus. They will perform “conscious sedation “ where you will be awake and able to respond to them but hopefully be in less pain so you can remain still for the procedure. If the injection is effective you’ve bought some time, but if not surgical intervention might be next step. You‘ve never mentioned physician therapy? Have they prescribed this for you previously?