Whilst I agree that you should get the DLC expansions, that may not be an option for you or you may not want to do that yet. (I played the base game without DLC’s on my first character then later on bought the DLC’s and since made 5 more characters so it is definitely “worth it” from my experience.
In terms of your current build - the skill point allocation looks quite messy to me. You are spread out across quite a few different damage types. Grim dawn (afaik) is a game where you want to focus on 1 maybe 2 damage types and then you can be more selective about the items that you find to match those damage types. It will also help you to pick out the right devotions - again to match the main damage type you want to focus on.
To make matters more complicated, certain skills/items in the game “convert” one damage type to another by a %. This type of stat is quite tricky so you might want to avoid it unless you know you want to specifically change the damage type into some other type.
Other than this, the main idea around making a build is to focus on a main damage ability - usually goes on your right mouse button slot, and then complement this with defensive abilities and other skills that can reduce the enemies resistances to the type of damage you are focusing on.
On the topic of resistances, as others have said above, you want to aim for 80% on all of them (except physical resistance which is much harder to get)
- elemental (fire cold lightning) resistance you can get easily from item stat and complement with components
- poison res you can use antivenom salve on belt slot
- Pierce and bleed res use silk swatch on pants/shoulders
- Vitality use soul shards in both rings
- aether res use aether soul in amulet/medal or purified salt on weapon/shield/offhand
Basically having the resistances up to 80 comes first and then if you have those capped you can use components for damage or other things.
Jump in to elite, check the resistances you are missing, then go back to normal difficulty and you can put in the required components to fix the resistances.
Also you may need to change out some of the items that have resistances as a stat on it because components alone might not be enough.
Once you have these things sorted you should be able to survive easier and also deal more damage to progress with the new difficulty.
edit:
I am definitely no expert but my suggestion for the skill point allocation is to put 1 point in curse of frailty and max out vulnerability from the occultist - this will provide enemy resistance reduction of 25%. You can remove points from sigil of consumption and solaels witchfire.
and for the arcanist skill points you can mostly leave it as is if you enjoy calidors tempest as your main skill otherwise you can consider changing to a trozan sky shard build and put all the points along that skill line up to star pact.
hopefully someone who is more of an expert can chime in and give further tips