Suicidal thoughts

Recently my life has been very complicated. My boyfriend’s grandmother has a lot of control issues and has been confirmed to be on drugs after everything she’s done (being seen by my boyfriend). We’re both 17 and have been dating for over a year. One night she had called my mother complaining he hadn’t come home yet (I had just walked in from work) and she said, “if he’s in bed with that whore daughter of yours I’m gonna kill her (me)”. I was at shock to hear all of this and so was my mother and of course my mom defended me saying I was at work. I think it’s important to clear up he’s the ONLY boy I’ve ever been with. Her torture continued as she took everything away from him and threatened that if he speak to me that she’d do unspeakable things to me. She’s been harassing me for the passed two weeks and last week I tried to kill myself but unfortunately people are good at their jobs and I had to come to school 2 days later. I’m so scared I’ve had the police at our school walk me to my car. I no longer can eat or sleep or focus at work or school. Everything has gotten too much. There’s more too the story but I only have but so much room. I really wish someone knew what I was going through. I’ve struggled with depression my entire life and when I met him it felt like I as getting better and for the first time in my life I wanted to live. But then everything happened and Idk anymore. I’m worried about him and myself. Any advice?