Idling issue when starting up with bouncing around and shaking.

I have a 99 Grand Am having about 270k on it. It has run great over the years with minor problems. In the past few weeks I have noticed that when I turn my car on after not being on for awhile it has a hard time idling and I can watch the RPMS drop really low like its going to stall out (it is an automatic BTW).

Anyway, It chugs and for the first few hundred meters of driving its rough bouncing around a bit and then tends to smooth out no problem. Today however I noticed that it started knocking in the engine so I checked the oil and its really low all of a sudden which I am assuming is causing the knocking. I am wondering if the starting and idling issue is related to the oil. This car does not get driven around very much as we have another car we usually drive.

BTW, when its having the problem idling at start-up, giving it gas seems to stop it at that very moment from shaking but it immediately starts again, it will only smooth out if you physically drive it somewhere.

Fuel pump has been replaced