I Don't Know What Else to Do

I'm stuck in a very difficult situation right now and I was hoping some people here could help me out with this. I'm 14 and I've been in a relationship with a guy for a year and four months. Everything's been going pretty well...except for the fact that I didn't tell my mom. She doesn't think I should be dating at all. I did tell her about him when I wasn't dating him just yet but she didn't think much of it. We had started dating in 2015 and we really do love each other...but from what my mom's seen she doesn't think he treats me well in the first place. My boyfriend and I and our friends had all planned to hang out in celebration of finishing finals for the semester. My mom wasn't too happy with this because my boyfriend was going to be there and she didn't want me hanging around boys yet. She misinterpreted his behavior as him being disrespectful to me, although I highly disagree. I'm an artist, so I've given him many drawings and he's framed them all. For our anniversary this past year, he gave me a photo album with tons of pictures in it, along with a very sweet letter. He's very caring  once you get to know him, but my mom doesn't see what I see. She had confronted me about him possibly being my boyfriend and I couldn't lie to her face so I didn't deny it. She told me that we had to just be friends. I told my boyfriend that we should put things on hold, but that didn't end up happening. At that point we had already been dating for a while and it's hard to and just be friends after being together for so long. When homecoming came around, my boyfriend asked me to be his date. I showed my mom and she actually let me go with him. This really confused me. I continued to date him, but just recently she asked me if I was dating him again. I told her the truth, but now she's feeling hurt that I disobeyed her. She told me the same thing she said when she confronted me the first time that we should just friends. I tried to explain that it wasn't that easy and she still didn't understand me. I would tell her how long we've been dating but she'd only feel more hurt. At the same time, though, maybe she'd see why it's not so easy to just be friends with him. She's threatening to talk things over with my boyfriend's parents and end everything and I don't know what to do. Advice would be much appreciated...