From a quick character search on the Lodestone, it looks like you've still got ilvl 385 gear equipped (though that may not have updated recently); you might want to upgrade your gear. Holminster Switch - the level 71 dungeon - drops ilvl 390 gear, and if you've got a bunch of Poetic Tomestones lying around, you can pick up Scaevan gear from Rhalgr's Reach and augment it with Scaevan Ester/Twine/Shellac (for Weapon/Armor/Accessories, respectively) by talking to the vendors there to get ivl 400 gear, which is equivalent to the gear you can get in Dohn Mheg, the level 73 dungeon. Focus on upgrading your weapon in particular - that dramatically affects how much you can heal for.