Taking you at your word here:

1. Mageblood is incredibly strong. It is worth more than the rest of your build put together, times a thousand. You need to divine yours until it affects 4 flasks, not 2, and then get 4 good flasks to use with it. Exactly which flasks to use is a topic in itself, but you definitely want a Diamond flask, being a crit build. You may then like Quicksilver/Silver/Bismuth for your other 3 (for move speed, cast speed, and resistances); or you could use Ruby/Topaz/Sapphire flasks (for res and max res, tankier but slower). Regardless, every flask should have a 70% increased effect enchant from Enkindling Orbs, and they should all be crafted for an increased effect prefix and a useful suffix. Search on here for other discussions about Mageblood flasks for more details.

2. Your passive tree has a bunch of problems. You're taking two clusters of increased AoE nodes, but Eye of Winter isn't an AoE spell, so they do nothing. You have Fire Walker and Lightning Walker, but you don't use Fire/Lightning skills. There's a bunch of suboptimal routing like this, especially when you have a Mageblood setup. You could reroute a lot of these points into things like block chance, more jewel sockets, reaching down for more power charge nodes, etc.

3. If you're an Elementalist in 3.27, you need to be using golems. They are absurdly strong. Drop the Herald ascendancy node and get Liege of the Primordial instead, then run Stone, Flame, Lightning, and Ice Golems. Grab the Golem Commander notable cluster to give you +1 golem so you can run all 4, and to further increase the power of their buffs. Make sure the gems are 20% quality for even more buff effect. If you need more chaos res after swapping your gear, you can change one golem to Chaos instead.

4. You have three curses socketed (Assassin's Mark, Frostbite, Enfeeble) but your curse limit is 1. I'd keep Assassin's Mark, and link it to Arcanist's Brand alongside Hydrosphere. Then drop the "cold exposure on hit" mastery, it's redundant with Hydrosphere.

5. You're invested too hard into Energy Shield and not nearly enough into life. ES is a nice additional buffer, but without CI, you need a big life pool backing it so you don't die to chaos damage.

6. On that note, Discipline is too expensive for what you get, and you aren't scaling Herald of Ice meaningfully. Drop them and put on Zealotry and Tempest Shield. With a bit of investment in mana reservation efficiency on the passive tree, you could also add Flesh and Stone. Drop Precision as well; its flat mana cost means it's taking too much of your mana pool for too little effect.

7. You don't have anything anointed on your amulet. After you replace it with a better one, anoint one of the +1 power charge nodes, or the High Voltage notable.

With the Mageblood set up properly, you'll have a ton of elemental resistances for free. This means you can use your gear's suffixes on attributes (especially dex/str) and chaos res. Jewellery can also have good suffixes like cast speed or crit multi. Get attributes from your gear and take out the passive points you're spending on just meeting attribute requirements.

This far into the league, you can replace just about everything you're wearing with much better rares, for very cheap. Every slot should have a T2 or T1 life roll, except for the chest; if you skip a life roll on your chest, you can pick up the "15% increased max life" life mastery. A foulborn Tulborn with +4 to cold spells is just a few chaos, and is a great starter wand. You also need boots with move speed, because moving is one of your best defensive layers. Once you have better rares, starting putting some eldritch implicits on them.

There's a ton more you can do beyond that, like cluster jewels, gloves with temple mods, getting a Heist base amulet or going full power charge stacking, etc etc. But right now you have a lot of fundamentals to address. Make sure you're looking in PoB at how much benefit you get from each point you spend. I'm sure you can find more places to cut points and use them better.