Help stuck in europe with a mondeo TD

[S1OWW]

Help i am stuck in switzerland with a ford mondeo turbo diesel 1994 L. It has been run on 50-50 filtered veg oil and diesel for a few weeks. Day 1, we drove 350 miles and as the fuel needle came near the red it started to judder, splutter and feel like it was about to run out of fuel. We stopped and filled up with diesel (40l) and 18l of oil. We drove about 200 miles and it juddered but not as much towards the end of the day, we then filled it to the top with plain diesel, left it over night and it was fine the next morning. Started fine and drove fine up mountain roads for 300 miles, the odd splutter but nothing bad until that evening and then it wouldnt pull under load. It got worse and worse until we struggled in 1st gear. It would stall as we pulled up to junctions, but would restart fine on the key.
It now starts and runs, but wont pull under load.

The pump has a plastic thing on top of the fuel pump (the fuel pump is at the front of the engine?) about the size of a 10p with lucus written on it,it has a few wires going into it, is that the make of the pump or the make of the electrical conector?

Could it be the fuel filter? can we clean it?
We thought if the pump had gone it wouldnt run at all?

We really need this car running, please please help.
We dont have much internet access, but will check when we can.
My number is 07702 256252

thanks

Paul