Try this
Your main issue is using a Sword/Shield & not having Empowering Might (EM) in an Altruistic Healing (AH) build. I've swapped Sword/Shield out for a Staff, as the Staff #4 "Empower" is an incredibly potent heal since you have AH.
Using a Hammer puts you in a predicament, but by no means is Hammer a bad choice. You have to choose either "Writ of the Merciful" trait or "Two Handed Mastery", you cannot pick both as this will mean you can't have EM which is a staple in AH builds. I've put Writ of the Merciful in the link as you mostly use Hammer #1/#2, so CD reduction isn't as useful. Try it for yourself and swap to Two Handed Mastery if you deem necessary.
It would be nice if you can comment which stats you choose for your armor. You want a mixture of Soldiers/Knights/Berserkers. You need Vitality, as Guardians suffer from low HP (16-17k HP is a good pool to aim for), aswell as Toughness to help mitigate some damage, aswell as increasing Precision with the trait. You also need Precision to proc EM, aswell as Power/Crit% to ensure you're not dealing junk damage.
You might want to check out
Strife025's build. He uses a GS instead of a Hammer, but its the same principle other than Hammer is lower DPS than GS, but a bit more supportive.
Keep us posted.
Edited by Xephenon, 25 December 2012 - 08:09 AM.