Ok after almost 4 entire days without A/C (and exhausting all my known troubleshooting efforts) I called someone..
Turns out our 'contactor' was bad, this relatively small piece of equipment. He replaced it within 5mins and now the A/C is puurrrring like a kitten! Very very nice, down to earth guy with more than reasonable pricing - so I will without a doubt recommend him!
He's based out of Lawrenceville, but traveled to Flowery Branch so I'm sure he does most of Gwinnett and obviously some into Hall co.