15 month sleep regression ??

My little girl has always been a great sleeper but for the past 6 weeks, she will NOT go to bed at night ☹️ It’s taking at least an hour, if not two, to get her asleep. She’s always had a consistent nighttime routine of bath, massage, pjs on, reading a story, then usually would nurse to sleep but recently she will just fight and fight, literally screaming until she exhausts herself and nods off. We can tell that she’s exhausted but just won’t sit still for long enough to actually fall asleep. She would usually have one daytime nap 1-3pm, which i’ve tried adjusting it & shortening it but then when we wake her, she can barely keep her eyes open and will just fall back asleep or is super grumpy for the rest of the afternoon because she’s tired. She’s had all 4 molars come through at once so i’m assuming that’s the reason but i honestly can’t cope anymore, i’m so exhausted from fighting her every night. Once she’s asleep she’s absolutely fine, it’s just the actual getting her to sleep that’s the issue. Has anybody been through a similar thing and actually come out the other side?? It’s been almost two months of this now and it feels like it’ll last forever, i’m at my absolute limit 🥲 Any advice welcome!! x