Family's involvement in my sex life.

Okay, I don't want to complain but I do need to rant. My family is very religious and I am not. In fact I have very different views of sex then my family members. I am 18 but I still live in my parents house because financially I am not able to move out as of now. Recently my mother has found out that up have been in a relationship. But she doesn't know that I am sexually active but she is suspecting it. I feel like whether to have sex or not it solely my decision, but my mom is threatening me that if I ever do, she will send me back to my home country. I'm not asking for solutions but I just wanted to rant. I want to make my own decisions and I think I have a right to do what I want with my body. I just wish my parents would accept that I am growing up and I will make my decisions.