Please repost and tell us how old you are now. And also tell us what your witnesses know. Are they "witnesses" only to how your life has been ruined? Only to what you told them? Or did they see something or hear the monster admit it? I want to be absolutely sure nothing can be done about him before letting this go. I know you do too.
You cannot personally prosecute anyone. Only the District Attorney can initiate a criminal prosecution.You do not say how old you are, but law enforcement agencies may not have followed up because it was too late for them to take any action.
Child molestation charges must be filed before the victim's 28th birthday. There is an exception if the first report to law enforcement is made within one year of the first report to law enforcement AND there is independent evidence of your allegation. If it occurred prior to 1994, when the statute of limitations was extended, it would also be too late to prosecute.
Please understand that this is a general discussion of legal principles by a California lawyer and does not create an attorney/client relationship. It's impossible to give detailed, accurate advice based on a few sentences on a website (and you shouldn't provide too much specific information about your legal matter on a public forum like Avvo, anyway). You should always seek advice from an attorney licensed in your jurisdiction who can give you an informed opinion after reviewing all of the relevant information.