It's not the Toughness that's the issue, it's how you are getting there. You have a ton of Dex and Vit, but are only hitting 12.2m Toughness. I say "only" because at that Vit value it means your mitigation is booty sweat. I haven't checked but I don't think the console uses the Dex -> Armor conversion for Monk & Demon Hunter, so it's more likely that your Toughness is further inflated by all the Dodge your Dex is granting, which is not actually mitigation (and honestly never should have been calculated into Toughness on their part). This is further compounded by the fact that if your mitigation is that low, and your health pool so high, you are putting maximum stress on your ability to heal; you need far more healing to recover the large chunks of damage you will take, and you have a much larger health pool to fill.
Basically, it says you have a lot of Toughness, but someone who had 10m Toughness that got there via Armor/Resist and only 3k Vitality would probably survive many times longer than you in any given situation, even on the same class. Now, it's not the worst thing on a Demon Hunter since you are likely doing a lot of kiting so you are likely eating big hits but not taking them that frequently, so having a lot of less-valuable Health isn't the worst thing in the world. But you'll fare a lot better if you can directly trade some of that Vit for All Resist and/or Armor, as it will increase both the value of your remaining Vit and your healing.