You don't say how old YOU are, but I assume you are an adult, correct? And since you are an adult, they have NO RIGHT to interfere with who you are dating or having a relationship with.
The only problem is that you're still living with them. They feel THAT gives them the right to interfere. They feel that since you're living under their roof, they can set the rules and tell you what to do. Why don't you move in with your boyfriend? Why are you still living with your parents instead of your boyfriend? Wouldn't it be better if the two of you lived together, or don't you think it would work out? If you don't think it would work out, then what's the point?
If you're working, why not try to get a place of your own? I think it's time you got your own place anyway, depending of course on your age! If you continue to live with your parents, you're going to continue to have these fights, probably regardless of what man you bring home. I doubt anyone will be good enough.
Best of luck and take care. I hope things work out. God bless. Hugs, Lee