oil out the timing cover drain hole? not good at all im afraid, sounds like a oil seal aint doing its job for a start. fuel system would be my first port of call for power loss, go back to basics and check every joint, re bleed etc then you can rule that out. intake system next check all joints and hoses, rev it and see if turbo pipe work is crushing in at all. failing that compression test her and go down block from there, ip timing etc.
good luck fella hope its nothing major!!!