After you are bubbled are you running to the appropriate colored circle to get your debuff cleansed?
First you must make sure you kill the orbs before they reach the boss. If they do reach him they heal him a lot.
Secondly make sure you clear your coloured shield. When you get lifted in the air you will get a coloured shield after you fall down. This will continuously damage you until it is removed, and the healer wont be able to keep up with the damage if you don't remove it. You used to be able to remove it with the templar's cleansing ritual ability. If you don't have someone with that ability then you have to go to one of the coloured circles to the left and right of the area. They will be either red or blue, you must go to the colour that matches your shield and it will remove it.
As long as you don't let the boss heal, keep removing the shields and make sure you keep the number of adds under control, it shouldn't be too difficult.