Loss of about a quart of oil and bogged down engine

Hello,

I was driving today for about two and a half hours today in snowy conditions with my car. Everything was running fine gauges showed that everything was good until I got to the toll booth. I noticed that the car had dropped in revs when I was paying the toll and then the check engine light came on and started blinking.
I was still on the thruway so I was trying to get the car off the road quickly to see if I could find out what was wrong. Then the engine started to pulse like it had power, didn't have power, had power, didn't, etc. I also noticed a burning smell as well.
I got to a gas station and checked my oil and I had lost about a quart. I had no idea why, maybe burning it, but not sure. I filled it up to operating levels and limped my car to my apartment. I'm not sure what wrong with it but it is still blinking the engine light at me and pulsing. Also sounds like the exhaust is staggered almost like a four stroke dirt bike slowly putting when I go to take off. My rev meter jumps around 1000 then down to 550-600 and engine sounds bad. Jumps down especially when I come to a stop. Any ideas?

Thanks,
Concerned car owner