Yikes! That's hard to swallow...and is serious. Oil is not leaking out from under the car I assume? You'd have to have a lot of smoke out back for that to happen...

We're not talking about sipping oil...that rate of consumption is much higher than the fuel consumption...and would be very noticeable while driving.

With all the other issues coupled in, sounds like you have a huge issue with the car, motor, drive train...never seen anything like that in my life....hope they / you get it sorted out very quickly. Something is not right.