I feel ignored and unsafe, I need advice to handle my mom and stepdad.

My dad died when I was a kid and my moms been with a man- (who we’ll call Derek) for nine years – so a few months ago I was playing Fortnite with my friend – speaking to him over discord using my phone while my mother was gone – Derek misheard me saying “I’m on four, I’m dead” (in which he thought me saying “I’m dead” as “I’m gay” and he has expressed his hate for the LGBTQ+ community very publicly) caused him to come into my room – yell at me – threaten to hit me multiple times then grab my phone and call my friend the f slur repeatedly – he kept leaving and coming back into my room just yelling about stuff – when I explained to him that he misheard me he just responded that he didn’t care and said that if I’m “still a sorry ass (n word)” when I grow up more then he might shoot me – I was both confused and terrified. Anyways he called my mom like he was in the right? She came back and picked me up but while doing it he said that she needed to cut my hair because “long hair is for girls, you’re raising a b***h.”, I explained to my mom what I said and she did believe me and told it to him and he said “I know what I heard” as if he didn’t say that he didn’t care when I told him that – that wasn’t the first time he’d done something like that – times when I was younger he had threatened my life many times and one time hit me for washing my hair which further adds to his mindset of “long hair is for girls” and i guess he was mad that I wanted to take care of my hair…?, I have/had a close relationship with my mom but I have showed and told her that I am scared of Derek and how he treats me but she doesn’t do anything about it – she acts like it’s nothing serious and that I have nothing to be afraid of, I brought this up to her like three times after it happened and she just dismissed me each time, right now I’ve told my mom that I just need some space and for her to not speak to me unless it’s very much needed and I’m worried how this will affect our relationship, like I don’t know if she’s just scared to lose her relationship with Derek or something but she has chosen him over family before (Kicking my aunt and some of my cousins out for almost hitting Derek with a tire iron because he had shoved her multiple times while threatening OUR lives because she was worried about my moms safety after hearing them argue with a clap sound ending the argument)
Like I really just don’t know what to do about this or how to handle it.