desperate need of help car now not running

so last weekend landy got a service , replaced fuel filter oil filter air filter & oil car running smooth , til friday seemed a bit slow so i accelerated a little and it chugged i was literally a street away from home to just took it easy til i got there , had a look on here and google but unsure what it could be , the car was running lumpy even idling was advised by mechanic to put in another bottle of forte injection cleaner , has about 8th of a tank of fuel , done this it didnt help , took it a drive wondering if it was the low fuel seemed a bit better at this point , put £50 of fuel in and proceeded to drive home , it was chugging badly managed to get it home , turned off ,when i tried to start again it was turning over but not starting at all sine then ive done the following

wastegate looks fine
modulator control valve has already been bypassed
there was very little oil on the red plug going into the ecu, cleaned that with brake cleaner
seems like its not getting fuel had the nanocom on it and its not showing any faults
the 1st fuel filter that was taken off at the service looked like the diesel was filthy so replaced it and topped it up with injector fluid ran fine for a couple days till this nightmare

any ideas ,

Model, engine, fuel etc would help people

landrover discovery 2 td5 , defender engine , diesel ,

i just changed the fuel filter , seemed to work fine took it for a drive round the block it became lumpy again and as soon as i got to the house it just cut out

back to the same issue its not starting

Check the fuel pressure / delivery rate at the FPR.

Cheers