Horrible engine noise?

[Logalegg]

So I have a small but potentially very big and expensive problem. My 04' started making a sort of rattle not too long ago and I was stupid and ignored it however a week ago driving to work this noise got very very loud so I parked it in the parking lot at work and left it there too scared to ride it. It almost sounds like a whining inside the engine even during idle I can still hear it but when I open the throttle it whines very loudly I added brand new oil. But any thoughts on what this could be?? I was thinking Cam chain or maybe the tensioner? any help is appreciated always come here for help love this place!!