Idle of doom and die

Nissan sentra, 1987, 123000 miles, 1.6liter, manual.
I got my oil changed today. When I drove out I noticed a burning oil smell, but it happened once before and was gone within a few days (maybe spilled oil or something so may not even be related to the problem I'm about to relate). Immediately after and up to 7 hours after the oil change no problem. Then (it had sat for about three hours) as I was driving home I noticed a shudder when accelerating. If I let up on the gas and reapplied there is a hesitation before reaction and the reaction felt as if I had released the clutch too fast (shudder and shake). It idles inconsistently with a lot of shuddering (as if its not getting enough fuel or random spurts of fuel) and will die if I sit for too long. Restarting is no problem, keeping it breathing is. Any tips or advice?