I heard from my garage and they confirmed it needs a new transmission to the tune of $3,200. Also, it seems to have sustained some sort of engine damage when I was revving it high to get it over to the shoulder of the road (shuddering and barely enough idle to keep it from stalling). Combine the reduced gas mileage and oil leak and I'd say it's headed for the junkyard in the sky.

I'll report back when I get my new/used ride which should be in the next day or two.