Idleing problem, my teg wants to die out

[Lewcis]

First off i'm a noob, but i'm a member of TI.net for about 4 years and this problem i'm having i can't seem to fix, and no one on there could really help me out either. I have a 94 5 speed acura integra LS, i now have about 110k, problem started with around 80k and is still going strong. Just took my skunk2 and put the stock exhaust back on. Other than that, i just have an intake. I get about 28 miles to the gallon, but i'm thinking it should be alittle higher since most of my miles driven are on a major high way going to school.

Started with me blowing my headgasket and ripping apart my car to fix it, while i was at it i rebuilt the head with new valves and such. When it was all said n' done, I started up the car and the idle has been bad ever since, its now going on 2 years and i can't take it anymore. On cold start up i don't get the high idle at about 1300-1600 my idle is at about 200-300 and is stumbling like crazy.
Sometimes after about 15 seconds the idle goes up to about 1100, but the problem doesn't stop there.
When i stop at a light and put my car in N, my idle will drop to 100(no joke, maybe even lower)
When it drops that low sometimes it dies out and sometimes it doesnt
When it doesn't die out it'll stumble around at about 100-300 for about 5 seconds then it will raise up to 800(but still is stumbling around and isn't running smooth at all)

Now for what i have tried
i've taken off the fiv valve and screwed the white screw in ALL the way
I've taken my intake off and covered the TB hole and it has died out. (which says i don't have a vaccum problem)
Today i took off the IACV and cleaned it all out with brake cleaner
I have replaced, distrib cap and rotor, wires and plugs and the most recent...getting a new o2 sensor reallll soon

Someone plz help, i think i covered everything