Good day, has anyone experienced this? Daughter hasn't slept for five…

Good day, has anyone experienced this? Daughter hasn't slept for five months. For about a month now she's been trying to regress sleep. At first it started with just changes in daytime sleep, often waking up crying and having poor night sleep. It was difficult, but I thought that after a month everything would be fine. But no! It only got worse. Now we have every single day both daytime and nighttime sleep is accompanied by a terrible tantrum before falling asleep. She sleeps on my arms, eyes closed and screams. Just doesn't understand. We have a clear schedule, we go to bed around 1:30-2:00 hours without overexertion, I watch for early signs of fatigue