Boyfriend meeting grandma

Hello all!! So my grandma is my legal guardian!! And I live with her and so like tomorrow my boyfriend is supposed to meet her and so today I told her this morning that like “Hey someone is coming to meet you tomorrow” and she responds “Ugh how do you know that I don’t have nothing to do tomorrow?” “I’m like grandma stop , you don’t , I checked your calendar” and so she says “Ugh fine I guess” And my boyfriend heard that and he hung up on FaceTime and so I texted him and said “Why did you hang up”? He said because my grandma is making it seem like she doesn’t even want to him. And so we were just on FaceTime a few mins ago and he said tell her I said hi and so then I said “Grandma my man said hi” and she said “You don’t got a man , you mean your friend said hi” and I told him she said that and he said “See she’s making me seem upset like she doesn’t even want to meet me” I keep telling him it’s gonna be okay, she just don’t accept the fact that I’m dating! She did the same to my ex, she always called him a “friend” when he wasn’t . So ladies I really need help, I’m really thinking about going to live with my biological mom because I can’t take anymore of my grandma! I am about to be 19 on Monday and she doesn’t accept the fact that I’m dating ? What the hell , I’m. Not breaking this relationship off just cause of her and I told my boyfriend that. I told him that she needs to accept the fact , weather she likes it or not! I’m so done with her. What should I do ? Please help me ladies!! I really need your advice! And also the things she’s saying makes him really feel upset . I keep telling him it’ll all be okay tomorrow. Please help ladies! Thanks , she’s also making me feel really upset right around my birthday