I didn't have the pain, but I have read here of others who have, and it seems to pass with time. But if in doubt, check with your doctor that it is OK to continue.
Musterbation is good therapy, and along with pump and injections, helps to keep everything working until we recover natural erections. Yes I know for the non-nerve-spared, there is only slim chance, but let's live in hope. Have you ever wondered why a slim chance and a fat chance are the same thing?
Like Billy, I find orgasms longer and more intense than before surgery, so there is an added reason to continue!