You likely need the engine completely overhauled.
The power is down because the turbo is not working properly, and the engine is generally worn out. It is burning oil because of worn rings, bores and pistons. The white smoke means that the head gasket is leaking.
I do not have the local knowledge to help you, but it may be better for you to get a replacement engine vs getting this one repaired, depending on local availablity and your financial situation.