It sounds like it could be pancreatitis. Im no docotor but the pain you describe, is a lot like mine and I have chronic pancreatits. Would be a good idea to have that checked out.
With the pancreas you can have pain worsened with eating anything. Fatty foods are really not good for the pancrease.
If the pain is severe and especially if you have a fever with it, and or vomiting. Yes, it would be a good idea to go to the emergency.
If not , then at least see a doctor soon and ask about the pancreas.