A year and a half post breast reduction, still have strong nerve pain around my nipples. Is this normal?

It sounds like you are still having regrowth of the sensory nerves to the skin which may be causing your symptoms.  Nerves regrow fairly slowly and may take a year or longer for that hypersensitivity and discomfort to subside.  However, at 18 months after surgery I would advise you to schedule an examination with your plastic surgeon. That's the safest way to be sure everything is as it should be!