Car suddenly stops(lagging) when hitting the throttle

I have an subaru impreza 2010 2.0 diesel. I already know these are known for their problems, but so far it has served me good, has gone 180 000km. But a problem has occured, when i hit the accelerator the engine jerks, losing all power then goes to full power. The rpms drop so it cant be the clutch. Im thinking it could be some sort of diesel related problem, but wondered if anyone here knew anything

Thanks in advance