HELP! I lied on my resume and used a fake refrence letter and now the employer is threating to sue me!?

I worked for a doctor a while ago and seen that the dr. was doing unethical things. I reported the dr. to OSHA and quit. Since then, anytime I apply at a new job and they contact my previous employeer, the dr. says I embezzled money and that I was fired. WHICH IS COMPLETELY UNTRUE! I asked the new offices to submit in writing what my previous employeer is saying about me but no one will. I contacted MIOSHA to file a complaint against the dr. for slander but they informed me that I had to have proof. I have tried telling new employeers the truth about the Dr. I worked for but it makes them nervous that I reported her.I have a new baby so I really needed a job.I was frustrated and desperate so a friend created a false refrence letter with the Dr.'s name on it. It only said that I was a great employee. The numbers on the letter were my friends. The dr. found out and is threating to sue me. I dont know what to do? How much trouble can I get in now? Please help.