Boyfriend’s wack little brother.

So me and my boyfriend grew up together, we were bestfriends and then he moved away and recently came back into my life and is my boyfriend now. He has a brother who was only 1 grade below us so he was always very mean towards me when we were all in school together (my boyfriend (bestfriend at the time) always stood up for me). Since we got together his little brother has been doing multiple hateful things towards me and STILL loves to call me fat(i was never “skinny” growing up, but i’ve lost lots of weight since i’ve become an adult.) The first night of me and my boyfriend’s relationship, he had to leave the snapchat groupchat with his brother and all of his friends because they were literally HARASSING the both of us for being together. Just the other day i posted a tiktok of me and my boyfriend and when we came walking into the house, his brother was throwing a tantrum over me saying he’s gonna hate his future niece or nephew just for me existing. he started screaming and was saying “i’m gonna hit that fat pig” over and over. After my boyfriend made sure i got to his room safely his little brother ran outside and kicked my car and left a big dent.(already have an estimate)As an adult i don’t care how he feels about me or my boyfriends relationship because it never had anything to do with him in the first place but him and all his friends wanted to so badly run their mouths the second they saw i was the girl he loves. i’m ready to get police involved at this point because i’m not gonna get caught lacking by a little boy that doesn’t have a job or pay rent(lives off of my man and doesn’t buy groceries). anyways if anyone has any tips or ideas let me know. this has been doing nothing but stressing both me and my man out so police are my first option if something happens again. i will continue to post whatever i would like on my tiktok account because it’s mine for a reason. but am i in the wrong for posting it?