Here is my take on some things I noticed you can change:
Stats
Enchants and gems will help with this, but your haste is somewhat low. Haste is great because it results in more rage through a lower gcd and also reduces the cooldown on Shield Block, allowing for higher uptime. Haste is your top secondary stat.
Along with this I see you are using double defensive trinkets. While they can have their use on difficult fights, in general you should want trinkets that increase your stats or contribute a large amount of damage.
Rotation
Your rotation overall looks good, with a couple exceptions. You are prioritising Shield Slam and Thunder Blast/Clap over Revenge, which is the proper way to play. You are also using Demoralizing Shout frequently, which is good.
One stand out issue is that you are not using Execute. As such your Deep Wounds talent point is completely wasted. Execute is somewhat poorly tuned, but it is still worth using over Revenge in single target. Use it when Shield Slam and Thunder Blast are both on cooldown. Otherwise you are better off taking the point out of deep wounds and into Battle-Scarred Veteran.
Secondly, you are overcapping on rage. You should aim to always spend rage before reaching your maximum rage cap at 130. Spending rage reduces the cooldown of Avatar and Shield Wall, so gaining rage while your rage bar is full is terrible for your damage and survivability. Use Ignore Pain (or Execute) if you are ever about to cap, even if you already have a full value Ignore Pain shield.
Last thing, your use of Shield Charge has some large gaps in it. You should aim to use it on cooldown. It provides Shield Block for free!
Defensives
Your Shield Block uptime is ~70-74%. You should want to be at least 90%, ideally 100%. The reasons are your haste level and use of Shield Charge. Shield Block is your most important mitigation ability! It also increases Shield Slam damage by 40% when active. Have it up at all times.