Why are you alone? Disaster Rags are all about zerging, zerging, zerging. Bring your Union, bring your friends, bring VoF to better apply debuffs and just AAB it dead. If you get 5 people of your powerlevel AABing the main body starting at the same time then you shouldn't have any issues. If you go in one by one, your debuffs will suck and you'll all just die without accomplishing anything.
Also, reminder that Fire Rag basically does nothing against you until after Turn10, at which point you just die. You die very dead.Exceed only helps you if you're hitting the burst cap of 1m. Which I very much doubt.
As said by dreamlitz, if you're in doubt of your prowess, you can always just run a support build. That means Joan or Andro builds.