On scale 1-10, how painful acute pancreatitis, and is the pain constant?

Depends. Everyone is different a 10 to one patiwnt is a 2 to another patiwnt.
Exceedingly. Typically, pancreatitis pain is pain induced with eating. This is because the pancreas provides enzymes and hormones needed for digestion, and when you eat, it triggers the pancreas, worsening the inflammation. Sort of like running on an inflamed knee. Pancreatitis needs to be evaluated by a physician to determine the severity and the possible need for hospital admission.
11. Pancreatitis can be an extremely painful and serious medical condition that often requires admission into the intensive care unit of the hospital.
Severe pain. Pancreatitis pain is constant, severe and located in the middle of the abdomen or back. Sometimes improved by leaning forward. I think most people would rate it a 10 for the pain level.
Pancreatitis. The pain can be constant and severe. Are you sure it is your pancrease (pancrelipase) causing the problem? You should be calling your doctor asap to be seen today.