2008 Chevy Aveo lurching/rumbling back and forth. Help!

So I have a 2008 Chevy Aveo (Black Betty) and she has been giving me grief for a good 7 months now. The engine light is on, and the only code that isn't throttle body related, (the dealership replaced my throttle body and didn't reprogram my computer afterward, I am working on that now,) is a P0303. Cylinder 3 misfire.
so the problem I am having is, most times when I start the car for the first time of the day, like 1 minute into my trip, the car will start being sluggish and refusing to accelerate past 20mph and it will also be lurching back and forth, like a slow but almost violent rumbling. It'll give off a burning smell, but all of my oils n juices are fine. Engine light blinking. So I'll turn it off for a good minute and then it's okay all day. Unless I take it on the freeway at all, it does the same thing once I hit 55mph. So I avoid the freeway. I am working w my dealership to reprogram my computer to accept the new throttle body. And I replaced the spark plugs and wires in my car about 2 months ago and it worked fine for a day and then went back to crap. I had a cylinder 2 misfire before the plugs n wires were replaced but it isn't there anymore, just the cylinder 3. A friend of mine suggested it could be an O2 sensor, but I am just trying to get another opinion. I miss the freeway and I don't want to damage my car anymore than I already have by letting it go this long. Help!