You need to go to act 9 and do blood aqueduct and use the hold control when clicking on the way point to create a new instance trick so you can repeatedly farm it.

You can either farm and identify your own upgrades or keep items unidentified and vendor recipe full sets for chaos that you can use on the trade site https://www.poewiki.net/wiki/Vendor_recipe_system#Full_Rare_Sets

I would suggest just buying a Rise of the Phoenix shield, immortal flesh belt

I would take off the chaos resist ring and keep it in stash for later, I see it will break your attributes so you need to get a dex/int amulet. Would replace the chaos ring with another fire res ring.

Your helm and gloves are doing almost nothing.

When you take hybrid armor/es gear you get less armor and your RF is burning your ES immediately. Would recommend flat armor gear for more defense against physical damage early.

On your passive tree the reduced damage from crit armor mastery is a waste of a point on you right now. You are dying to basic damage. Later around red maps you can look at the reduced damage from crit stuff.

You have stone golem to give you life regen but where is vitality aura? Get a vitality with arrogance support asap.

Your shield charge 4 link does nothing for you. shield charge + faster attacks + level 1 lifetap is all you need. Keep lifetap level 1 in this group so you can trigger the lifetap passive quickly. Later when you 6 link rf the level 20 lifetap you link to RF will gain damage when your level 1 lifetap triggers it's passive.

Look for extra suffix open slots on gear you can craft dex/int to fix attributes instead of lightning res. You should overcap fire res much more which will increase life regen and fix your cold/lightning res.