I'm having what feels like pinched nerve pain on my waist left side only. have some spots on my left side that is numb. what should i do?

Shingles possible: Red marks that are bumpy or blistery and associated with pain are often shingles. If there is a rash or bumpy skin, most likely. Antivirals work best early in onset of the symptoms. If you have not had, i would suggest the shingles vaccine. If otherwise doesn't radiate, and not shingles, could be disc herniation low thoracic region. Try nsaid's, rest, ice/heat, and seek doc if not getting better.