You don't describe the actions of the idiots you're grouped with, but your gear seems good enough to me. Surprised to see something other than
Jerkin of the Untamed Spirit in your chest slot...little less stam but double the armor of what you've got.
Regardless, I think grossly sub-par gear would lead to "death" a lot more than "losing aggro" unless it's consistently your healer that's drawing aggro because of having to spam fat heals on you. So as usual, I blame those DPS knuckleheads. : )
Single biggest problem with holding aggro is DPS hitting targets other than the one you're concentrating on. Periodic mauls or swipe hits won't keep a mob stuck to you against the damage of any DPS class/toon who's really hitting them.
Make sure every target in every pull is marked. I don't know how universal the use of the symbols is, but in my experience it's Skull for first-to-die, then Red X, then Yellow Star, with Orange Condom and/or Blue Moon designating crowd control.
If DPS focuses on burning them down in that order, you're able to throw just a little damage onto Skull, X, and Star to get them on you, and then focus on keeping Skull REALLY pissed off at you. Your DPS support can usually nuke away unless they outgear or outlevel you, and you just hit targets 2 and 3 every once in a while to stay above healing aggro which is AoE. Just before your current target dies, start paying more attention to building aggro on the next target to get a headstart so DPS can wail away.