2 buttock injections/B-12/Fentanyl, severely bruised/hematoma/left with 2 painful lumps, cant walk, pain shoots down leg/1 yr already?

Sciatic n. Injury. Difficulty walking & severe sciatica for one year & post-injection of medicine into ipsilateral buttock suggests mass-effect/permanent type of injury to sciatic nerve. See a Neurologist for confirmation. Knowledge of a medical misadventure does not begin until the sufferer learns, from an expert, that it has occurred. A most unfortunate circumstance if this is indeed what occurred. Iatrogenic?