Never take block rating or parry gear unless the other stats on it make it an upgrade. Block is a bad stat right now it just doesn't stop enough damage and parries diminishing returns are much higher then dodge so you always want to take dodge over parry if you can.
Your hit and expertise are really low but that is more a threat issue.
Stacking stam is never a bad way to go. More health can't hurt for a warrior ( any tank really ) And get dodge as often as you can for avoidance.
Your spec is ...... bad imo. Spell reflect is a waste to have in your main tank spec and you would probably do better to just copy the standard deep wounds build till your confident enough to change it. It's the best all round spec.
A question about that fight though... when you get 2-3 stacks ( depending on if it's 10 or 25 man ) of the armor debuff is another tank taunting off you till they fall off ? You only seem to do 10 mans and if he's hitting you for 20k I would assume you're getting full stacks and dieing.