Before anything else... it's not 'axe tank' it's either Marauder, or Warrior.
Next you need to ask yourself is this content Leveling / post-50 / RAID... since each of these works very differently as to how you have to approach it

Healing is as much about your weapon / gear as it is about the tanks. If they are too poorly geared they take too much and the incoming spike damage of trash packs will kill them. If you are too poorly geared (weapon out of date) you will not be able to maintain healing throughput for a fight (skill wise this also has to do with are you over-healing regularly). Use the time you have between battles when you have high mana regen to cast damage shields on party members to save you mana when you need it, and make sure you're using Shroud for MP or enmity whichever is more dangerous in the fight.