You have incredibly low mana and spell power, your spirit is a tad low as well, and you are doing the cardinal sin of wearing non plate gear.
You need to stack more int as soon as possible, then up your spirit to a level that can sustain your healing style. You also have next to zero gems or enchants (This screams at me I am not ready for Heroics).
Take the time to get your gear set up properly and you will make it incredibly easier on you and your groups ability to get through heroics. This is a huge pet peeve of mine right now, between healers, tanks and DPS jumping into heroics because it shows up in the dungeon list, and not being even close to ready to do so.
If you're doing under 7-8k dps, you should not be in a heroic.
If you are under 75k mana, 5k spell power, and 2k regen, you should not be in a heroic.
If you cant break 125k hp unbuffed, and are not close to the Expertise/hit caps, you should not be in a heroic.
The vast majority of pugs failing, and griping about heroics difficulty do not have the gear to warrant them even being there. Can you do these will stats below this? Sure, but if everyone in the group met these requirements, you would not struggle based on gear, only on execution.