No one in my family likes my bf

I (23F) really need advice on what to do or say. I have been dating my boyfriend (25M) for three months today but known each other four months, I will call him J for this post. J has ADHD and is very socially awkward, his family has also been really strict and a bit judgy in the past like suggesting he and his twin brother have autism which was never proven. He is used to people thinking he is weird or stupid so he overcompensates by saying literally everything he knows about whatever topic is being discussed, he is very nerdy, likes stuff like DnD and has a blog where he analyses and reviews movies, he is a huge gamer, as am I. This is my first genuine relationship, I have been with other guys just not in a committed relationship before, I started online dating last year during the summer and had one guy where I thought things were going well but then he dumped me after a month, then about four days later I met J and he’s been amazing, he’s very sweet and caring towards me, he genuinely cares about me and how i’m doing, we’ve gone to seattle comic con together this year, it was our first long distance trip together and it was great, we have great sexual chemistry but more than that we understand each other, our morals and things we want in life line up with each other, I think he’s very attractive. I am 300 lbs at 5’6 and yet he says as long as I am healthy (not skinny) he doesn’t care about how much I weigh, he says he finds me insanely attractive inside and out. Overall the relationship is great, we have plans to go on a two week trip to florida in June to meet his father, I am so happy with him. Now, my aunt and cousin apparently do not like him and I do not understand it at all. I get that he has his quirks when interacting with people but I have seen him interact with them and I did not see anything he did wrong, the only thing they have been able to say is “I have a feeling he is going to hurt you”. I should add that my family has always been very close-knit, they literally live in the same neighborhood as me and my younger sister. My aunt doesn’t really say anything bad about him but my cousin on the other hand has said to my younger sister that she thinks he is going to hurt me and it’s just a feeling she gets, she thinks he’s weird, apparently she thinks I didn’t “take time” to myself after that one guy dumped me before I met J (I cried it out for two days and was over it, the guy was an asshole and I genuinely didn’t care about him). I have MDD so they think I am so fragile but I have been on meds for over a year, have a job and take care of myself, there is literally no reason for them to think i can’t handle a relationship. My cousin also told my younger sister that she thinks I don’t say no to my boyfriend in terms of him asking if i want to go somewhere or do something with him (I have said no plenty of times to things and he always asks if i want to before making plans). I went down to my cousins house to talk to her and my aunt about how they felt because i didn’t want anymore drama, my cousin said that she would support me even if she doesn’t like him as long as I’m happy and am not being abused. Even after that she hasn’t told me how she really feels about him and has been off with me and tell my younger sister how she feels instead of me because she thinks i’m going to get mad. At this point i have made my peace with it because it’s my relationship not theirs and they do not have perfect relationships whatsoever. The thing that’s really hurt recently is my younger sister not liking him. She did not say she doesn’t like him but thinks they do not get along well, they have been around each other 4 times total mostly cause she is an introvert. She says that they have nothing in common like the kinds of games, shoes or movies they like and apparently he hasn’t tried getting to know her (asking questions about her) I talk about her all the time to him because my younger sister is literally my best friend and it turned into a whole argument because I didn’t understand where she was coming from at first and by the time I did, she was pissed and I was crying (I cry during arguments due to trauma, i’m working on it lmao) and now I just feel horrible and idk what to do or say to make her feel better. J has tried talking to her about things she likes and it usually turns out that he isn’t into the same thing and he explains why he isn’t into it and she takes it as him shit talking what she likes. I’m honestly at a loss and would appreciate any advice. Thank you!