I think you just need time and practice, I am a shadow tank and have been tanking LI for almost a year now.
It is never a good idea to blame others, when things go south, I am inclined to think the problem lie's with yourself.
The reason I say this is, if you wipe with one group, fare enough, but if you wipe with every group then you must look to yourself.
Your build is a little low for tier 2, and my advice try to get a hold of a shield amplification relic, EV drops a lot of them.
The shadow rotation is just as important as the build, not just for you, but for the rest of the group, since you are also healing them for 6%, also using guard can be a good thing or a bad thing.