I discovered a small bump on my lower/middle back it feels hard i tried to pop it i can't i had a nerve block a lil before i found it .. help im scared?

Lump on back: There are lots of causes of bumps on the back. The most common one is a lipoma, a small collection of fatty tissue, that is completely benign; you can just ignore it. Other causes includes block sweat glands, scars, fibromas (benign fibrous tissue lump), warts, or a granuloma, which is an inflammatory reaction to any irritant in the skin. These are benign also and will heal on their own.

Have a Look: First, i'd schedule an appointment with the provider who performed your block. Ask if there might be some connection. If not, he/she may refer you to a dermatologist for a second opinion. Second, don't be scared! the likelihood of the "bump" being a serious issue isn't high. Best of luck!