Volvo V50 1.6l diesel

Hi Scotty..  as above I have V50 Volvo..  it's like it's in limp mode. Won't rev above 3000 revs, lack of power..  I've replaced(with new) mass air flow sensor, airbox to turbo ipipe (had a tear), EGR valve, turbo pressure solenoid valve, all with no effect...  It's intermittent as when I first start it revs fine, then as I drive away it's low on power and won't rev above 3000.  I've noticed the actuator arm moves slowly up or down when starting, this is why I replaced the valve...   Really has me at a loss now..   car comes up with NO codes or faults..Car has 360000km on it but normally runs fine, this only started 3 weeks ago.  Please help me 🙏🏻😭 I don't know what to try next and it's getting expensive..

Regards from Ireland

James Ryan