Not a dps race? Prob u are speakin about another boss... Ve had today two tanks 14k plus 5dps around 25k and we had all pulls finished around 6% due to enrage...
Keep hanging in there. You may be able to get away with swapping a healer for dps. Yes, it's going to be tight, and it means a shorter timer, but it does more dps.
You're almost there, tho, and I wish you the best of luck on killing this guy.