So sorry for the anxiety you are going through. Not being authentic is stressful and also living with others who pressure us to live inauthentically or fear judgment and rejection.
Regarding some housekeeping matters - obtain your SSN card, key papers - diplomas, identification, insurance information, research your states/ city's resources for homeless/ youth.
Here's a good article about the subject on Reddit: https://www.reddit.com/r/TheGirlSurvivalGuide/comments/1wciql/im_getting_kicked_out_what_do_i_need_to_know_to/
Stay positive. Don't turn bitter. Shower all with kindness and decide now what moral principals and standards you will keep as an adult going forward and then be open and honest with them. You are worthy of dignity and respect even if you hid a boyfriend. You can acknowledge the truth about how your actions may have been less than honest and hypocritical. You can also decide what your new position will be going forward.
Wishing you speed in landing on your feet and to finding the best bath for your highest good.