[3.20] Looking for Advice with CI Occultist HoAg Build (Uses Spells to Apply Virulence)

Link to PoB: https://pastebin.com/NQi82uRq

- I use the Occultist Ascendancy for an extra curse, some ES regen, and immunity to freeze. I found it added more PoB-calculated tankiness and damage compared to the other Witch ascendancies. I didn't have enough spare characters to field test the difference.

- I use 3 cluster jewels (1 large, 2 medium) and 2 unique jewels. The medium cluster jewels both add Pure Agony, and one gives a socket for the Golden Rule. My other jewel is Energy from Within, located north of the Witch starting area.

- There are 3 trees and 2 skill + item sets. Two of the trees are my final plans for the build; one (named Tanky) is simpler than the other and doesn't use cluster jewels. The other (named Damage) was a test, because I couldn't account for all the potential changes between the trees in my head. It turned out to have much more DPS and EHP but less flat ES, so I kept both trees. The final tree and secondary skill + item sets are all labeled Field Test, and are the items, skills, and passives of the actual character used to test the build. I didn't have all the items in the build, which can account for some of its shortcomings, but it should be viable already at level 90 and I'm not happy with the meager 1.6M DPS PoB says it'll have when maxxed out.

I've tested the build in various scenarios, and it doesn't seem to perform exceptionally well in anything. I don't know what specifically it needs, so I'm coming to you guys for help. I want to be able to finish all endgame content reasonably well. The build doesn't need to be able to do all map mods or be the best in any type of fight, but I want to kill all the bosses and survive most/all league encounters. The following is a list of things I tested it on.

- Delve: Died twice at depth ~116 very quickly. I didn't have enough clear speed, and the crawler kept falling behind and abandoning me to die.

- Maps: A bunch of tier 1-3 maps, along with a tier 5 or 6 map. It finished all the maps, but there were a couple times where my health took a concerning dip or the mobs didn't die quickly.

- Breach: I did one breach and almost died twice.

- Delirium: I did one Delirium encounter and almost died a few times.

- Harvest: I did one Harvest encounter and, you guessed it, almost died a few times.

- Betrayal: I killed Catarina, but died once.

I use Ice Spear with spell echo, unleash, and greater multiple projectiles to stack virulence. The support gems let me hit a ton of times in a single cast, and I use the Golden Rule to increase my virulence gain. Since I use CI, I take no damage from the poison. To let Ice Spear apply poison, I use The Consuming Dark dagger and an abyssal belt + abyssal gem adding chaos damage to all spells.

I use Herald of Agony linked to Damage on Full Life, Empower, Minion Damage, Vicious Projectiles, and Vile Toxins. I have two cluster jewels with Pure Agony, and the crawler has a 25% chance of gaining Onslaught and Unholy Might on kill. I use skitterbots to shock and chill, and my stone golem gives me Feeding Frenzy. I apply Despair and Vulnerability for damage, and use a spectre that grants frenzy charges.

I'm running a CI Occultist, so my health pool is Energy Shield. I've got a shield that gives me a ton of ES, and I invested in some block (26% block chance, 42% spell block chance). I mainly use ES regen to sustain, which I get from Zealot's Oath and a ton of life regen mods. I get extra ES regen from my Stone Golem. I have two manually triggered survivability skills: Vitality, which grants 400 ES/second; and Focus, which recovers 27% of my ES instantly. I have Vitality in March of the Legion for the extra ES regen and the freed-up mana reservation (I still need enough mana to cast the aura, but I can use the mana for other spells while it's active). I also use Enfeeble, which reduces enemies' action speed. I use Vixen's Entrapment because it's pretty cheap but gives a lot of ES compared to my rare gloves, it gives an extra curse, and it triggers socketed curses when I cast a curse.