I haven't looked at your log, but I can see from your log that you're gemmed, enchanted and reforged wrong. This is most likely why SD is probably up so little. You should never reforge out of mastery (unless it's the only stat on a piece), and stam stacking died with Arthas.
Hit and expertise are pretty much non-factors for a tank since taunts and interrupts can no longer miss. Thus, your hit/expertise enchants should be replaced with agi or dodge. You should also be reforging Haste > Hit > Expertise > Crit > Mastery (in that order) to dodge on every piece you have. There's absolutely no reason right now for a bear to choose to reforge mastery over hit.
Finally, lose the straight stam gems and replace them with straight agi unless you need to pick up an agility or mastery socket bonus, or to activate your meta.
Doing these things will increase your mitigation and avoidance, allowing your healers to conserve more mana by not healing you.