The diesel Galaxies from the factory were fitted with dual mass flywheels to damp vibrations and provide smoother drive and torque, which also gives the driveline an easier time. Because dual mass flywheels are prone to failure and costly to replace people sometimes choose to replace the whole clutch and flywheel setup with a solid flywheel and clutch to suit, but this isn't a miracle fix, because the transmission, clutch and driveshafts are subjected to more vibration and stress.
If you bought a clutch intended for the factory fitted dual mass flywheel then it won't suit the solid flywheel, but I don't know what the difference in price between the dual mass and solid clutch/ flywheel kits is, I would expect the solid flywheel kit to be cheaper because it's simpler to manufacture.
If you plan to get rid of the car fairly soon and assuming your solid flywheel is in a re-usable condition then your cheapest fix will be just to replace the clutch and pressure plate with one intended for use with the solid type flywheel.
