How to improve this build (Crit Discharge Guardian)

My main goal is to be extremely hard to kill, and i'm satisfied with it's tankiness so i'm mostly looking to improve the dmg without reducing defenses.
RN I can do juiced T16 no sweat, facetank most bosses but i feel like my damage is very low to do Guardians & up.
The main idea is to use Storm Secret to hit often to quickly generate charges for Discharge. I want to keep most uniques like the boots & shield, replace weapon, jewels & belt with better rares maybe but what mods to look for?
I don't know what to upgrade first & my budget is ~3 divines. I know it's not a lot but what would be the "most bang for my buck"?

Thank you!

pob: https://pastebin.com/jZewJ9xf

to improve damage on discharge you would want to get as many charge balls as you can.
at least
+1 on helmet
+1 on weapon
all +1 charge balls on tress
than change amulet to badge of the brotherhood
now you get +8 on both power and frenzy balls.

thank you very much Wally!