AHHHRG! 300td drama. Debris! NEED ADVICE PLEASE!

Hi,
I wish I could have joined this forum under better circumstances, but I'm having a bit of a crisis. I've had low oil pressure, around zero at idle on in-dash PSI gauge, which jumps up a little unevenly and doesn't peg until 2000+ RPMS.

I decided to change the oil pump after changing the oil filter shaft o-rings with no change.

So I remove the old pump to find 12 or so ball bearings inside of the screen. There is also pieces of the cage which held the balls. They are about the size of the balls in a bicycle hub maybe 3-4 milimeter.

My questios are:

1) Where is the bearing from????

2) Will replacing the oil-pump possibly help? If not I can still cut my losses and return the pump.

Any other advice is welcome. I am stuck in my shop as this is my daily car so please respond!