What to do about my protective mom?

I know, this may be silly to some of you. I'm 16 years old, and I'm in a wonderful relationship that's lasted two years. I have a driver's license, and my mom is really really protective. It really just seems like she doesn't trust me, and I've never given her a reason not to. If I ever actually get to go anywhere, which isn't often at all, I'm always where I say I am. I don't lie about my grades. But it's just recently that my mother has been acting like I'm sneaking around, and I truthfully haven't done anything wrong. She especially acts this way whenever I want to go somewhere with my boyfriend, because she thinks I'm just going to sneak off with him, and I don't, and I won't. She thinks my horomones are enraged, and despite popular believe...they aren't. And everytime I even mention my boyfriend, she's always badmouthing him...just because he doesn't have a license and can't afford to get a car. He's been trying to hard to get someone to take him to get his license, and to get a job just to get her off his back...and I just feel like it's not right she acts that way. I don't know what to do, so...help?