Dating a boy with a reputation (need major advice)

So I’m 18 and after being friends for awhile I’ve started dating this boy. We’re kinda complete opposites, and admittedly when I first met him I jumped to conclusions too. I thought he was just this wannabe bad guy who was way too pessimistic and who probably wasn’t a good person. As we got to know each other better I realized that I was totally wrong! Under that hard persona he’s such a kind, smart, and genuine guy. He’s so, so sweet to me and always makes sure I’m comfortable and taken care of. The only thing is, is that it takes awhile for him to warm up so to most people he still comes off as this unfriendly guy.

When I introduced him to my friends and mom, they all immediately jumped to conclusions as I had and didn’t want to believe he was anything more than how he looks/acts. My friends talked about how they heard he’d get into fights, or how he’d have bad habits and all this other bad gossip. They said that they don’t trust him and that he’s just trying to get into my pants, which isn’t true. He hasn’t made any advances and even said he wants to take it a bit slow. My mom’s opinion matters the most since she’s my best friend, and she isn’t his biggest fan either. She immediately ridiculed him for having so many tattoos, being unfriendly/ cold, how he’ll break my heart, how he isn’t the type of guy I should spend my time with, etc. She thinks he’s changing my behavior and making me more irresponsible.

On top of all this he’s getting hurt. It seriously weighs on him that people think so little and in turn I feel terrible and like I’m causing him trouble. I also hate that I’m arguing with my mom about all this and causing her stress. It’s just all a bit messy and I’d really love some advice, thank you!