I received an anonymous threat from an email I do not know of. Threats to out me and more.mCan someone do a reverse email trace for me? I need to know who it is coming from. It's very urgent. Need help ASAP.

where would be off shore blackmailers threaten people unless they send them money via Green Dot Money Packs, or some similar scam.

Did they convey any information that would let you know that they know something about you other than your email?

If so, then you might want to speak to a lawyer about your options and how to remain anonymous in the whole affair.

If you don't know any lawyer you can contact your local bar association, explain what the problem is, and let them recommend some lawyers who have expertise in the matter.

I hope this gets resolved easily, whatever it may be.

It's nothing like that. A provider gave my info to one of her clients. He has my address, medical history, and names of my family members. He has threatened me. What should I do?

will lead to his undoing.

People are surprisingly unclear on the law regarding this and he could face up to ten years in prison in most states for extorting you.

By the way, extortion does not even have to involve a request for money or other consideration.  Just placing you in fear unlawfully is enough to secure a charge.

If I was you, I would approach a lawyer about how to defuse this situation in a way that protects you the most.

And now I should add:

Still not a lawyer

I would definitely agree with mrfisher on this.  See a lawyer if at all possible.  

..you trace the e-mail.  

You should take this to an attorney first.  This is either the Gal or her BoyFriend/Pimp.  Keep all communications.  A PI might be employed to track down who is doing the threatening.  I would not want to go to the POLICE without an attorney because you don't want the Police to go on a fishing expedition...    
You are being extorted.  You are the victim.  Extortion is a FELONY.  You are a citizen who deserves protection & the criminal charged (though your interest might be that this go away.)  Sometimes stalkers & scammers vanish if they realize they've been id'd.  In stalker cases, a lawyer's Cease & Desist demand letter on his letterhead sometimes have the desired effect with least muss & fuss.

The emails ended up coming from the provider herself, not the client to what I have found. It appears as if the extremely personal details were found through a simple search of my name. She is all bark and no bite and I don't think she will follow though with anything, it's been more than a month now. In the future I should think twice before sharing such person details with someone.

just Google you information weekly for a while.