1500 hps and 31% armor is extremely low for empowered monolith progression. At a minimum, you should be in the 2000-2400 range and 50-55% armor. In the short term, perhaps reallocate some of your damage nodes to the Forge Guard tier 1 talent that gives 6% physical resistance and armor when hit. It won’t show up immediately on your stat sheet, but it will quickly become a factor in your survivability.
You might also look for items “of the Ox” (% health), of the Giant (+hps/+% health) or of Life (+hps).
For mobility, make sure you are specced into either Lunge with the additional charge (top of the tree) or Smite with the talent that teleports you to your target. I’ve been playing a lot of boardman21’s Void Apocalypse build, though with more of an emphasis on Abyssal Orbs than the DoT effects. You can literally dash past the monsters and let Devouring Orb do 75% of the work for you. It’s a great Void Knight mobility build if you’re struggling with melee (which many people do at higher content since range has an inherent advantage of controlling distance and damage).