Problem with my land rover discovery

Its a clasic symtom of a turbo failure or blocked air filter.

Black smoke is an indication of too much fuel being delivered and the engine is essentially "flloding" itself.
Most likely a mass air flow sensor or throttle body issue. Try cleaning the body first.
ps
White smoke is a head gasket
Blue smoke is piston rings.

You have the cheapest smoke issue to fix.

if you look at the reverse of the fuel pump you will see a 13mm nut holiding a 10mm bolt. undo the 13mm lock nut and turn the 10mm in or out to adjust the mixture, this is easy as you can run the engine with the adjuster lose so you can high rev it and adjust all the black smoke away. dont go too far or your power loss will be devastating, you need to listen to your engine and look for smoke at the same time. i always leave a little black smoke at the high end of the revs this will give you enough power but wont black out the street.

Replacment of the fuel pump would not sound to far off.
The noise you are hearing sound's, like the catalytic converter is falling apart,inside,replacement ,would be in order

Yep, that's the engine!
Seriously though, is it a TD5 Diesel? Is it more of a squeal? If so, it'll be the exhaust manifold.

Change the Mass Air Sensor it is dirty should solve all your trouble

Have you checked the High-Low ratio lever.  Half-way between High and Low is a Neutral, so no drive to any axle even if a gear in the main box is selected.
Try locking the differential.  If this gives you drive, then it might be a final drive (half-shaft) failure.

need to change a new pump.

i experienced something very similar, we checked everything and found 2 issues . 1 ; on chassis in front of diesel tank is a sediment filter, ours was full of jelly and silt. and also on top of diesel tank through trunk outlet and return diesel pipes partly corroded and pulling air in. swapped sender and cleared silt pot and amazed by the power difference too. hope this helps ,Reuben