Are there other girls (part 2)

Recap: (My sexual partner recently told me that he tested positive for an STI) Many of you from part one told me to go and get tested. But there’s a big problem there. Even though I’m 18, I still live under my parents roof and I HAVE to tell my mom. Crazy thing is, I’m more afraid of how my moms going to act than about my health/contracting the STI. If I tell her then she is going to give me hell for MONTHS. I’m not even exaggerating. The first time she found out I was sexually active (lost my virginity at this time btw) she beat the HELL out of me (pulled my hair, threw me against the wall, kicked, called me derogatory names), I was isolated, didn’t eat for 2 days (by choice... not that she noticed 🙄,) was called a “hoe” and “fast,” she stopped kissing me and telling me goodnight/ ily. I got really depressed. And that was just sex, how will she react when she finds out that I’ve contracted an STI?!?! SHE DOESN’T EVEN KNOW IM SEXUALLY ACTIVE! Ugh, I’m just not ready to go through that again. Till this day she says that she can’t get over it and hasn’t forgiven me. She parents out of FEAR not love. I can never talk to her ab anything! I know that I have to be mature ab it and just tell her that I need to go to the Gyno, but can you guys at least give me some advice on how to talk to her???