Iveco Daily 35S14 Running on 50% power?

Can someone help please!

This happened over night.
One day it was running on full power, than parked it for the night. Than the next day it was running on about 50% power and the injector light started flashing. It is like the turbo is not working, but I can hear it humming.
Rather the engine is not getting enough fuel. It is really hard to go up hill sometimes 45mph top speed.
On straight road 65-70mph top speed.

There is no smoke.
The engine purrs like before, except no power.

I have been running SVO for about 6000 miles.
Just changed the fuel filters.