Water in the Oil

It sounds like it could be a few problems.

Bad head gasket(s).
Cracked head(s).
Cracked Block.

It seems like you have a bad coolant to oil leak. The reason your oil pressure is gone is because the antifreeze has found a way into your oil through a hole in a gasket, head, or a hole in the block. The oil can't build pressure because it's either being flooded with water, and/or it's flooding into the coolant system as well.

If the car won't idle, then it seems the problem is pretty severe and needs repair. If it will idle, I suggest trying a couple products I've had success with in the past.

Bar's Leak Copper Block Seal, and Bar's Leak Head Gasket Repair. I suggest starting with the Copper Block Seal, as it's for permanently repairing serious leaks you'd find in the engine block, whether it's cracks, holes, or whatever.

I suggest buying the cheapest oil and filter you can get for the car for the purpose of having fresh oil in the car while you're patching the leaks. The last thing you want is water to enter your bearings and destroy them. Change it with good oil if the treatments seemed to have worked.