How to wean stubborn one year old

Baby is 14 months and nurses for naps and bedtimes. She gets laid down while still awake and falls asleep on her own. I have attempted to wean her from nursing by just rocking her and/or singing to her and she goes absolute bat shit crazy as soon as she realizes I’m not nursing. I’m talking head butts, total tantrum mode, like injury’s. I’m not sure how to proceed? I’ve made a lot of attempts at this over the last month and it’s the same response every time and she does not give up. I really hate to just get her in her jammies and lay her straight in her crib and let her tantrum by herself in there, is that what I’m going to have to do?? My first didn’t put up any fight when I weaned her so I’m at a loss. She’s so stubborn and I can’t in good conscience let her get that out of control for longer than like five minutes or else I’m afraid she’s literally going to hurt herself. She’s such a calm and easy going baby with ererything too so I’m just shocked at how she’s responding to this. Do I just lay her down and let her figure it out and leave?