Don’t get benediction until later. Get consecrate and make a beeline for imp righteous fury, blessing of sanctuary, and holy shield.
One of the issues with prot is that they really don’t shine in their intended role as AoE tanks until 51 when they have cons, sanc, and holy shield. After that point, they absolutely dominate anything involving many mobs; other tanks get worse with multiple mobs, but paladins actually get better due to the nature of most of their threat being reflect damage. Top all of it off with a shield spike on a crest of retribution from strat later, and you’ve got a recipe for wholesale slaughter.