Steps to try:

1. Get a fuel injector cleaner and add to your almost full tank).
2. Get a "carb" cleaner spray clean up the linkages that operate your
throttle and related links.

The idea is that the fuel injectors maybe "dirty", hence limiting fuel
flow. The second thing is that throttle plate may not be closing all the
way to the limits. These 2 things will cause the engine computer to
incorrectly set the fuel-air mixture settings, hence the engine rough
idle.
(bad oxygen sensor or bad throttle position sensor aka TPS will also cause
this  problem .... but I would do this after I tried the cheaper options).