Virgin, but not believed....

I have a very strict mother (I’m a 15 year old upcoming junior). I had my boyfriend over tonight and we played video games, watched a movie, and listened to music. He left around 10 pm. Unfortunately when my grandparents came over they closed my door (my mom wants my door open when my bf is over). After he left she started accusing me of having sex and doing stuff, threatening to not let me see him anymore and getting birth control shots. I told her that I never have done any of that and I wouldn’t do it, but she won’t believe me.... my mouth, hand, or vagina has never touched a 🍆..... I need advice please this is very important to me and this is ruining my reputation in my family 😔