neither of the screws you point at are the one you want.
first - the idle fuel screw is not the one you want - you dont want to play with the
fuel mix circuit (or you didnt - but you have - so now you need to fix that as well)
you want the Idle adjustment screw. (idle speed screw)
right ? you did say all you wanted to do was adjust the idle speed correct ?

second - the screw you did adjust was in fact the idle mixture screw - which , by adjusting
the air\fuel mix changed the idle speed by increasing or decreasing the fuel mixture at idle
so you 'thought' you'd done the right thing - but in fact- as you noticed , all you did was get
change the air\fuel mix- now your bike doesnt run right- or idle correctly.
try and put that back exactly where it was -

the 2nd poster sent a great PDF - you want the screw that changes the opening on the throttle slide.
your cable should be slack - start with that - make sure that you can turn the throttle just the slightest
bit at the bar ad turn the bars in both directions without changing the idle speed -
once the cable is perfect, then adjust the idle speed .

the air\mixture adjustment you played with - you should turn it in(clockwise) till it JUST begins to idle
faster then back off an eigth of a turn .
then readjust your idle speed one last time.

should about nail it.

g'luck
marc