I am sorry for your situation, but ilf there was never any promise by you to pay rent and you never did, then the law sees you as a guest who can be told to leave at any time; no three day notice and unlawful detainer action is needed. You might be able to sue him; if you are under the age of 18 sex with him would be statutory rape on his part. You should not have put yourself in that position and you need to break it off as quickly as possible, so his asking you to leave is not all bad. Since you did not ask any specific questions, l do not know if this answers your immediate concerns.
