Something about how gearing works in PoE escapes me. I can't seem to balance resists and sockets and everything else I need. I got to Act 6 and I'm getting destroyed, its frustrating.
Well for starters, don't try to get any chaos resistance. Even if you are -30% that's fine.
If you are above 50% on res in act 6 that's fine. You can find other ways to get some tankiness, since you are in act 6 you have all the gems available to you now.
Here are ways to get some tankiness:
*Use a Melee skill for movement (Whirling Blade, Leap Slam, Shield Charge) and attach Fortify to it. If you are using Leap Slam you even attach Endurance Charge on Melee stun for extra tankiness. You can attach Blood Magic as the final link so you can spam the skill without worrying about mana.
*Combine Warlords Mark with Blasphemy for an aura that gives you a ton of life and mana leech along with Endurance charges on kill. On the flip side you can also combine Temporal Chains with Blasphemy to slow down enemies considerably.
Remember that color sockets work based on the item, so don't try to get all greens on an intelligence/blue item especially early on, you will be throwing away your handful of chromes.
*Defensive flasks are good to have. You should have freeze, curse and bleed immunity on your flasks. You should also have Basalt flask and/or Granite/Jade flask as well for defense along with offensive ones like Silver/Sulfur flasks. You don't need 3 life flasks, you can make do with just one. It's easy to craft flask and they can hold you off even into the end game.
*Attach Immortal call to cast on damage taken along with another defense skill like Vortex and/or a golem or curse. Immortal call can save your ass a lot.
*If that's not enough, get more auras like Purity of Elements or defensive auras like Arctic Armor.
*Make sure your leech and/or regen/recharge is up to snuff as well, can't be relying just on flasks for sustain.
Though in my experience, if your damage is good enough you can kill them and flask/leech your way through the pain at this stage of the game.
If you are still having trouble then there is probably an issue with your build in general. Most people don't have enough life/ES in this stage of the game which hurts them the most.