Your gemming is a mess. Very wierd to see an expertise/mastery gem ('fine' parry+mastery in red sockets is better), or to have green gems in prismatic (or red) sockets. You are missing enchants on your gloves (mastery or greater mastery) and bracer (dodge). You've made some seemingly strange choices with your valor purchases (the cloak is really good, the thrown not much better than the quest reward from the new instances).
Overall, it looks like you are unclear what you are trying to achieve with your gearing. You should read around on "Combat Table Coverage" or 'CTC' on this site, there are plenty of threads on the topic of ensuring you have enough mastery to at least block (if not dodge/parry/miss) every boss swing. Most warriors aim to be at or near full CTC in this tier of gear. If you understand what that is, and instead choose to go the stamina root then that's your decision - but at least be consistant.
But. The first few bosses in normal mode really aren't that tough, so it's also highly likely that you are also doing the fights wrong. On Morchok, that means 2 tanks taunting off each other before their debuff goes too high. On Yor'sahj, that means switching tanks when void bolt stacks high (and you might consider breaking out the baradin hold mirror trinket for that). Zon'ozz does hit fairly hard, gear will be a factor here, but so will smart use of cooldowns as his damage ramps up. It's his big frontal 'psychic drain' that is the killer, so try to have some kind of cooldown up for that when he is getting hurty. If you understand the fights and make good use of your active cooldowns in response to the mechanics, you will increase your survival significantly.