90-100 dungeons are nearly impossible now

I am currently leveling a level 97 shaman with full heirloom gear. Following the patch today, I qued up for a dungeon. I was given Slag Mines, where everything is now scaled to the players level. All enemies were very difficult, each trash pull took 3-4 minutes. What was once an easy dungeon to run through is now putting me oom during trash pulls. Can blizzard PLEASE rebalance these dungeons? We couldn't make it through the second boss.