1998 nissan altima

my nissan acts as if it wants to cut off when i'm at stop lights waiting. i
got new spark plug wires, spark plugs, change air filter and cleaned out
dirt inside of that. when i turn own the a/c it does it even more. a
couple of times i thought it was going to just quit. my a/c is screaming
when i accelerate like a cat is caught underneath the hood or something.
it only screams when the a/c is on and i accelerate from 0 to about
leveling off at 55 then it stops screaming.please help me

If it has a separate v-belt that drives the A/C compressor, you may need to
replace it. You might as well replace the serpentine belt that drives
everything else while your at it.

You have probably already got this fixed by now but as far as the rough
running even after you replaced plug wires and plugs, fuel filter,
etc.etc., You might try running some Lucas fuel injection cleaner through
your gas. It not only cleans them but also lubricates the upper portion of
your engine. Use one bottle per tank and do it a couple of times and then
change out the fuel filter. I would say you might have a bad O-2 sensor
but that should cause the "engine light" to come on and stay on until it
is fixed.
Be sure your pug wires are also on correctly. Our 98 had a problem getting
mositure build up down in the hole where the plugs set. The car sets
outside under a carport so I'm not sure if that doesn't help or not.