LAND ROVER RANGE ROVER SPORT ENGINE SYMPTOM

My Car Was Fine, Had Stopped At Traffic Lights Then When I Pulled Away My Car Was Juddering And Had A Lack Of Power, Message Came Up...

Engine Won't Turn Over, Just Hear 2 Clicks? Also Didn't Accept A Jump? Drained Battery? Help Please!

Just Changed The Motor Oil And The Motor Lost Power. The Accelerator Is Sluggish. The Engine Is Knocking. I Added 3 Liters Of Lucas Stop Oil...