For anyone who's interested, the short story "Eleven Hours Out" from the anthology Tales of the Dominion War tells the story of the Breen attack on Earth
As for the Dominion pushing through all the Alpha lines with the help of the Breen superweapon and a general numerical superiority... I don't think it would have been that easy. The superweapon essentially requires you to fire one direct hit at every enemy vessel you want to neutralize, so there would have to be lots and lots of super-armed Breen ships present in every one of your attack fleets. And we know the superweapons were a bottleneck. Probably the battle of Chin'toka saw a great massing of all the super-armed ships for the desired strategic effect, and it would have been very difficult to mount another campaign like it immediately afterwards, let alone multiple campaigns. Think Cambrai in WWI, with the first massed use of tanks leading to a very short-lived success and then a long, long period of waiting and preparing another tank attack.