You only get a total of 9 shard. 1 every two week. It’s advised to wait on built vault for that. Or push until you can clear +3.
Looked you up to try see the credibility with your stories. As I play Prot warrior too. Mine is 587. I think we play different on many levels. Magic damage is not as bad as what people meme about it.
From what I been reading here, your main issue, and looking up your build. You drop Shield Block too often. You should try to min max your shield block charges. (Part of why haste on warrior so good.) it’s a game changer and many warriors don’t do it.