Give yourself some time to get better gear, get the mana pools and spirit you need to heal sufficiently. It has only been 5 days. 5 friggin days! I doubt all of you have leveled to 85, and geared yourself up already.
Heroics are hardmode, if you cant heal heroics, DONT DO HEROICS. There is non-hardmodes for a reason. Go back to the regular dungeons, get some better gear, fix your style of play. Then come back.
Im tired of reading all the whining that is going on, on this forum. Its always gimme gimme gimme, just because the game is a little more difficult now, you dont want to play anymore... what is wrong with you!? The difficulty is half the fun, and is what makes completely a heroic, and keeping your team alive feel good. Isn't that why you rolled a healy in the first place?