FUCK THAT DUMBASS BITCH!!!
First off, clean house and take any computer or hard drive the fuck out. Second off, nobody can just fire you on a whim or heresay, it's not like some bitch is gonna call up your employer and tell them you juice and need to be tested, they won't do that....and for reassurance I'm gonna tell you why....you go to your employer first and send a formal email addressing an angry girlfriend who is threatening you and you are afraid she may bring trouble to the workplace. Dude, if she kills herself over this YOU DIDN'T PUT HER IN THAT SITUATION. She was mentally sick and gonna do it anyways!
Next, you fucking leave. It's as simple as that, you leave. Now, this next part is the most critical part, you need to document and record everything!!!
If she sends a nasty text then save it. If she mentions performance enhancing drugs you respond with "well all I use are supplements from GNC" , never admit to shit!!
You get enough on her to make the bitch sound crazy and you will be fine. Next, you take that evidence to the police and get a restraining order on her.
You don't let her know where you move to, you block her fucking #, and you move on!!!