As a general rule, an employee cannot be fired for not wanting to sleep with the boss. However, your case is very complicated, and I cannot give you specific advice unless I meet with you to discuss your situation. If you would like to meet, I would be happy to provide a free consultation.
Please understand, however, that this message does not constitute legal advice but is general information, you should not rely on any of the information contained herein for your matter, and we have no attorney-client relationship until you meet with me and sign a retainer agreement.
This is a complicated situation which, if handled properly, may allow you some compensation to go forward with your new life. If he dismisses your employment, you should immediately contact an Employment Rights Attorney to discuss your options as well as applying for unemployment. It would be beneficial for you to move out of the residence before you are put into a very awkward situation as you have minimal rights as a gratuitious guest in his home.
A consultation with a good general practice attorney could help your discover your options.