dealing with his family

so me and my boyfriend are both 18. seniors in high school. and we’ve been together for two years. his family hates me because i’m too shy. even after two years they don’t want me around. they don’t let my boyfriend see me outside of school. he promised me that when he turned 18 everything would get better. well he’s been 18 for a while now and nothing has changed. he says he won’t stand up for me because he won’t disrespect his dad. how should i take that? like i’ve been with him for two years. busting my ass off to be with him and try to get his family to like me and nothing has worked. and it feels like everything we have doesn’t mean anything to him because he won’t tell his dad to lighten up. or even just be nicer to me. how am i supposed to tell him that this hurts me? everytime i mention it he always says he can’t do it because he can’t face the consequences. should i stay or should i go?