Cluster Feeding?

Hi guys. I joined because I can't find anything online that covers the situation we're in. Hoping someone here can provide reassurance or offer advice .

My SO gave birth to DD 7.5 weeks ago, 12 days early by elective section. She's our first and she's lovely. My SO is EBF.

For three weeks now, almost on a nightly basis, DD has been doing what we understand to be cluster feeding. From around 7pm until midnight she does nothing but scream, cry and feed. She eats a lot, but midway through feeds she comes off the breast inconsolable and is sometimes too agitated to come back on, creating a vicious cycle. She's acting like the hungriest girl in the world, despite having had a number of massive feeds. Sleep is unthinkable for this period, even trying to settle her just makes her go more crazy. So we (well I just stand there trying to be helpful, really just my SO) just go with it. The bright side is baby usually sleeps from 12.30ish until 5ish and then has a couple more big sleeps after.

Before I get on to my main point, is this cluster feeding? From what I've read online, cluster feeding is when baby has lots of little feeds, is fussier than usual but sleeps in-between the feeds. The internet says that we might expect a few consecutive nights like this, but we've had 3 weeks and counting. Is this normal?

Ok but the above isn't why I'm here. Today the feeding began at midday and has been pretty constant since. It's 10.35pm where I am and the baby is starting to settle. She hasn't slept since this morning. If this happens tomorrow should I be worried, or is this all normal?

Thanks!!!!

PS DD was born around 6.5lb and is now like 9.5lb so we're not worried about that