It might be a coincidence that the turbo has failed (or is failing) at the same time, but the exhaust pressure is what drives the turbo and the EGR opening affects the exhaust pressure. Swilling exhaust fumes in the intake manifold affects it too, which is the more common issue.
If you can take your EGR pipe off, make a blanking plate for the exhaust side of the tube out of 1mm stainless or better. You can make one for the intake manifold side as well, to ensure no boost leaks (which might also be your problem).
D22s have different turbos to D40s - which model is yours? D22s use a wastegate, D40s use variable vanes. The D40s can be upset by a poorly sealing vac hose.